What is the biggest sin for a Christian?
Eternal sin
Thomas Aquinas lists, or has responded to, six sins that supposedly go against the Holy Spirit:
Thomas Aquinas explains that the unforgivability of blasphemy against the Holy Spirit means that it removes the entrance to these means of salvation; however, it cannot hinder God in taking away this obstacle by way of a miracle.
Western Christianity
Although "original sin" can be taken to mean the sin that Adam committed, it is usually understood as a consequence of the first sin, the hereditary stain with which we are born on account of our origin or descent from Adam.
With the exception of tendencies such as Pelagianism, Western Christianity is thought to hold this doctrine, which was championed especially by Saint Augustine, who wrote: "The deliberate sin of the first man is the cause of original sin" (De nupt. et concup., II, xxvi, 43).
Nikolay Guryanov
Once he was asked what he considered to be the most dangerous sin in the souls of people? Father Nikolai answered: "Unbelief! This is frightening." - Even with Christians? - "Yes, even, with Orthodox Christians".
Contrition
A central concept in much of Christianity, contrition is regarded as the first step, through Christ, towards reconciliation with God. It consists of repentance for all one's sins, a desire for God over sin, and faith in Christ's redemption on the cross and its sufficiency for salvation (see regeneration and "ordo salutis"). It is widely referred to throughout the Bible, e.g. Ezekiel 33:11, Psalms 6:7ff, Psalm 51:1–12, Luke 13:5, Luke 18:9–13, and the well-known parable of the prodigal son (Luke 15:11–32).
Confession (religion)
Typically, the penitent begins sacramental confession by saying, "Bless me Father, for I have sinned. It has been [time period] since my last confession." The penitent must then confess what he/she believes to be grave and mortal sins, in both kind and number, in order to be reconciled with God and the Church. The sinner may also confess venial sins; this is especially recommended if the penitent has no mortal sins to confess. According to the "Catechism", "without being strictly necessary, confession of everyday faults (venial sins) is nevertheless strongly recommended by the Church. Indeed the regular confession of our venial sins helps us form our conscience, fight against evil tendencies, let ourselves be healed by Christ and progress in the life of the Spirit. By receiving more frequently through this sacrament the gift of the Father's Mercy, we are spurred to be merciful as He is merciful". "When Christ's faithful strive to confess all the sins that they can remember, they undoubtedly place all of them before the divine mercy for pardon." As a result, if the confession was good, "the sacrament was valid" even the penitent inadvertently forgot some mortal sins, which are forgiven as well. As a safeguard not to become something like "subconsciously inadvertent" to avoid saying some sins, these must be confessed in the next confession (if the penitent then remembers them; or generally in the first confession in which they are remembered). Even then it is allowed, however allowed, and even, except for certain devotional purposes, generally sensible to concentrate in one's examination of conscience on the time since the last Confession.
Sacrament of Penance
Practically all writings of that period, for instance "The Shepherd of Hermas", "Didache" or "Letters of St. Ignace of Antioch", show that grave sins were not rare among Christians. Cyrille Vogel collected a list of twelve major sins named in the New Testament and the Apostolic Fathers' writings. They are all various transgressions of the Ten Commandments:
Christian theology
The Greek word in the New Testament that is translated in English as "sin" is "hamartia", which literally means "missing the target". 1 John 3:4 states: "Everyone who sins breaks the law; in fact, sin is lawlessness". Jesus clarified the law by defining its foundation: "Jesus replied: 'Love the Lord your God with all your heart and with all your soul and with all your mind.' This is the first and greatest commandment. And the second is like it: 'Love your neighbor as yourself.' All the Law and the Prophets hang on these two commandments." ()
Blasphemy
Blasphemy has been condemned as a serious sin by the major creeds and Church theologians (apostasy and infidelity [unbelief] were generally considered to be the gravest sins, with heresy a greater sin than blasphemy, cf. Thomas Aquinas' "Summa Theologiae").
Thou shalt not bear false witness against thy neighbour
The Catholic Church teaches that "A lie consists in speaking a falsehood with the intention of deceiving." According to the Bible, the Lord denounces lying as the work of the devil: "You are of your father the devil, . . . there is no truth in him. When he lies, he speaks according to his own nature, for he is a liar and the father of lies." (John 8:44) Lying is the most direct offense against the truth. To lie is to speak or act against the truth in order to lead someone into error. By injuring man's relation to truth and to his neighbor, a lie offends against the fundamental relation of man and of his word to the Lord. Lying is a mortal sin when it does grave injury to the virtues of justice and charity. Lying is a profanation of speech, whereas the purpose of speech is to communicate known truth to others. The deliberate intention of leading a neighbor into error by saying things contrary to the truth constitutes a failure in justice and charity. The culpability is greater when the intention of deceiving entails the risk of deadly consequences for those who are led astray. By violating the virtue of truthfulness, a lie does real violence to another. It affects his ability to know, which is a condition of every judgment and decision. It contains the seed of discord and all consequent evils. Lying is destructive of society; it undermines trust among men and tears apart the fabric of social relationships.
Christian views on sin
Roman Catholic doctrine also sees sin as being twofold: Sin is, at once, any evil or immoral "action" which infracts God's law and the inevitable consequences, the "state of being" that comes about by committing the sinful action. Sin can and does alienate a person both from God and the community. Hence, the Catholic Church's insistence on reconciliation with both God and the Church itself.
List of Christian denominational positions on homosexuality
Most churches that are within the Pentecostal Movement view homosexual behavior as a sin. The second largest Pentecostal Church in the USA, the Assemblies of God, makes its view clear on homosexuality in a position paper stating: "It should be noted at the outset that there is absolutely no affirmation of homosexual behavior found anywhere in Scripture. Rather, the consistent sexual ideal is chastity for those outside a monogamous heterosexual marriage and fidelity for those inside such a marriage. There is also abundant evidence that homosexual behavior, along with illicit heterosexual behavior, is immoral and comes under the judgment of God."
Christian deism
This may give the Reader some Notion of this Writer's Candour and Sincerity, and what we are to think of his pretended Regard for Christianity, which in Effect amounts to this: That the Christianity revealed in the Writings of the New Testament is Jewish Christianity; that is, Christianity corrupted and adulterated with Judaism, which according to him is the worst Religion in the World. But the true and genuine Christianity is Christian Deism, to be learned not from the Writings of the New Testament, but from the Volume of Nature, from every Man's own Breast, from the Heavens, the Earth, and especially the Brute Creatures,the genuine uncorrupted Instructors in our Author's Christianity. So that the "Gentlemen that assume to themselves the Title of Deists, seem resolved that for the future they only shall be called the true Christians too. Those that look upon the New Testament to be divinely inspired, and receive it as the Rule of their Faith, and take their Religion from thence, must be called Christian Jews, who only put a strange Mixture of inconsistent Religions upon the World for Christianity : whereas these Christian Deists teach it in its Purity, and in order to propagate pure uncorrupted Christianity they do their utmost to discard.the Writings of the New Testament, that Is, the Writings that give us aft Account of the Doctrines taught by Christ and his Apostles, But since these Gentlemen will not allow; us the honorable Title of Christians, it is but fair that they should leave us that of Free-Thinkers, to which I really think the Advocates for the Gospel Revelation have a much juster Pretension than they.
Theology of Søren Kierkegaard
Sin is separation from God but despair over sin is separation again. Kierkegaard said, "The consciousness of sin definitely belongs to the consciousness of the forgiveness of sin." Why would someone sit and reflect on sin to such an extent that an eternal happiness is exchanged for an eternal unhappiness or even a temporal unhappiness? This reflection is done in time but the consequence of the reflection leads one to lose hope in the possibility of any good coming from oneself. Kierkegaard says Christianity invites the single individual to become a partaker not only of the consciousness of sin but also of the consciousness of forgiveness but we seem to concentrate on the former to a remarkable degree. He said the following in "Three Discourses on Imagined Occasions" (1845) and "Practice in Christianity" (1850):
Alcohol in the Bible
Christians are instructed regarding abstinence and their duty toward immature Christians: "All food is clean, but it is wrong for a man to eat anything that causes someone else to stumble. It is better not to eat meat or drink wine or to do anything else that will cause your brother to fall."
Immorality
In Christianity, sin is a central concept in understanding immorality.
Actual sin
In Roman Catholic theology, the "Capital vices" or sins, also known as the "seven deadly sins", are the main roots of sin. They are called capital sins not because they are the greatest sins or necessarily mortal sins, but because all sins are in some way related to at least one of them. These sins are:
Christian denomination
Christianity has not been a monolithic faith since the first century or Apostolic Age, if ever, and today there exist a large variety of groups that share a common history and tradition within and without mainstream Christianity. Christianity is the largest religion in the world (making up approximately one-third of the population) and the various divisions have commonalities and differences in tradition, theology, church government, doctrine, and language.
Jewish views on sin
Sins between people are considered much more severe in Judaism than sins between man and God. Yom Kippur, the main day of repent in Judaism can atones for Sins between man and God, but not for Sins between man and his fellow, that is until he has appeased his friend.(Mishnah, Yoma,8:9). Eleazar ben Azariah derived [this from the verse]: "From all your sins before God you shall be cleansed" (Book of Leviticus,16:30) – for sins between man and God Yom Kippur atones, but for sins between man and his fellow Yom Kippur does not atone until he appeases his fellow.
David Flusser
Flusser pursued his research at a time when many Jews blamed Christianity for Nazism. During his trial in Israel, the Gestapo officer Adolf Eichmann refused to take an oath on the New Testament, insisting he would swear only "in the name of God." Flusser commented in an editorial in the "Jerusalem Post": "I do not know who is the God in whose name Eichmann swore, but I am certain that it is neither the God of Israel nor the God of the Christian church. It should now become clear to the strongest Jewish opponents of Christianity that Christianity "per se" imposes limitations, and that the greatest crime against our people was not committed in the name of the Christian faith".
Lust
Adultery: One of the main forms of lust seen frequently during the Middle Ages was the sin of adultery. The sin of adultery occurs when a person is unfaithful to his or her spouse, hence "invading of a bed not one's own," (Pg.235). Adultery is a special kind of ugliness and many difficulties arise from it. When a man enters the bed of a married woman it not only is a sin, but it "wrongs the offspring," because the woman now calls into question the legitimacy of children. (Pg.235). If a wife has committed adultery before, then, her husband will question if all his wife's children are his offspring. 
Simple fornication: Simple fornication is having sex with one's wife for enjoyment rather than for bearing children. Fornication is also sex between two unmarried people, which is also a mortal sin. Aquinas says, "fornication is a deadly crime," (Pg.213). Fornication is a mortal sin, but as Aquinas notes, "Pope Gregory treated sins of the flesh as less grievous than those of the spirit" (Pg. 217). Fornication was a grave sin such as that against property. Fornication, however, is not as grave as a sin directly against God and human life; therefore, murder is much worse than fornication. Property in this case means that a daughter is the property of her father, and if you do wrong to her, you then do wrong to him; therefore seducing a virgin or seeking pleasure from an unmarried woman is an invasion of a father's property.
Forgiveness
Forgiveness is central to Christian ethics and is a frequent topic in sermons and theological works. Considering Mark 11:25, and , that follows the Lord's Prayer, "For if you forgive men when they sin against you, your heavenly Father will also forgive you. But if you do not forgive men their sins, your Father will not forgive your sins.," Forgiveness is not an option to a Christian, rather one must forgive to be a Christian. Forgiveness in Christianity is a manifestation of submission to Christ and fellow believers.
Indulgence
"When a person sins, he acquires certain liabilities: the liability of guilt and the liability of punishment." 
A mortal sin (one that is grave, or serious, in nature and is committed knowingly and freely) is equivalent to refusing friendship with God and communion with the only source of eternal life. The loss of eternal life with God, and the eternal death of hell that is the effect of this rejection, is called the "eternal punishment" of sin. The Sacrament of Penance removes the guilt and the liability of eternal punishment related to mortal sin. "Though your sins are like scarlet, they shall be white as snow; though they are red like crimson, they shall become like wool."
Libertarian Christianity
The most obvious point where results of these two hermeneutical agendas conflict is in regard to so-called victimless crimes. For example, comparison of the relative attitudes towards victimless crimes held by prototypical secular libertarian, Murray Rothbard, and the prototypicial Christian libertarian, Andrew Sandlin, shows that secular libertarianism and Christian libertarianism are not particularly compatible. From the libertarian Christian's perspective, the comparison shows that Christian libertarianism's attempted amalgamation of secular libertarianism lacks rational integrity. Libertarian Christians believe this lack of rational integrity in the Christian libertarian legal philosophy is a symptom of Christian libertarianism’s erroneous hermeneutics. Rothbard:
[T]the most important argument for Prohibition was the undoubted fact that people commit significantly more crimes, more acts of negligence on the highways, when under the influence of alcohol than when cold sober. So why not prohibit alcohol ... I submit that there is only one why not, and this should be no news to libertarians who presumably believe in inalienable individual rights: namely, that no one has the right to coerce anyone not himself directly engaged in an overt act of aggression against rights. Any loosening of this criterion, to include coercion against remote "risks," is to sanction impermissible aggression against the rights of others.
Libertarian Christians believe that this prototypical secular libertarian argument applies with equal logic to all so-called victimless crimes. Secular libertarianism, according to Rothbard, gives no place to the state for punishment of victimless crimes. The same cannot be said for Christian libertarianism according to Sandlin:
[T]he state must punish murder (Ex. 21:12), theft (Ex. 22:1-4), idolatry (Ex. 22:20), and other sins that the Scriptures explicitly requires it to punish. Since we may deduce from Scripture that abortion is murder (see Ex. 21:22, 23), that copyright infringement is theft, and that the public worship of the Earth by New Age advocates is idolatry, the state may suppress these crimes.
In a secular state, according to secular libertarianism, idolatry is a victimless crime (or rather, shouldn't be a crime at all), and to punish it would itself be a crime. Biblical standards of morality call for the proscription of libertine behavior, such as drug addition, alcoholism, prostitution, gambling, and idol worship. Theonomic Reconstructionists and Christian libertarians generally believe that wherever such behavior is made morally repugnant by biblical standards of morality, the secular government is rightly authorized to punish practitioners. Libertarian Christians believe that in regard to victimless crimes, the secular libertarian position is more rational and more consistent with the Bible than the Christian libertarian position. In contrast to Christian libertarians, libertarian Christians believe that behaviors that violate biblical standards of morality, but are nevertheless victimless crimes, are rightly punished only within the ambit of the visible Church, and should be dealt with otherwise through free market processes. Libertarian Christians believe that secular governments are never authorized by Scripture to punish such immorality unless there is undeniable proof that a contract has been broken or real damage to another person’s property (including this other person’s ownership of his/her physical body) can be proven beyond a reasonable doubt.
Catholic theology
Sinning according to the Greek word in scripture, "amartia", "falling short of the mark", succumbing to our imperfection: we always remain on the road to perfection.in this life. People can sin by failing to obey the Ten Commandments, failing to love God, and failing to love other people. Some sins are more serious than others, ranging from lesser, venial sins, to grave, mortal sins that sever a person's relationship with God.
Nathaniel William Taylor
At the heart of this objection is Taylor's view of the atonement. Many Christians believe that Christ's death upon the cross was as a sin-substitute, whereby the sins of mankind were imputed to Christ, who was punished for our sins in our place. Martin Luther went as far as to say that Christ became the worse sinner in the universe. Christ's righteousness, or his perfection, was then imputed to all believers. Consequently, God no longer sees believers as they really are but is blinded by imputed righteousness. For many Christians, this belief is the cornerstone of the Christian faith. Yet Taylor explicitly denied this view.
Islamic views on sin
This Quranic verse indicates that "khati’ah" is considered an "ithm", a grave sin. In fact, the word "khati’ah" is associated with some of the most heinous religious sins in the Quran. In one Quranic verse this word is used to describe the sin of slaying one's own children for fear of poverty. (Quran 17:33/31). Scholars believe that "dhanb" or "ithm" could be used in place of "khati’ah" in this instance; however, the word choice indicates that "khati’ah" is more than just a moral lapse or mistake and is punishable.
Great Commandment
When asked which is the greatest commandment, the "Christian New Testament" depicts Jesus paraphrasing the Torah: "Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind," before also paraphrasing a second passage; "Thou shalt love thy neighbor as thyself." Most Christian denominations view these two commandments as, together, forming the core of the Christian religion. The second passage is considered to be a form of the Golden Rule (circa 1300 BCE).
Christian views on sin
Speaking about sloth (Lat. "acedia") Thomas points out that every deed which "by its very nature is contrary to charity is a mortal sin". An effect of such deed is the destruction of "spiritual life which is the effect of charity, whereby God dwells in us." Sin of a mortal character is always committed with the consent of reason: "Because the consummation of sin is in the consent of reason"'. (cf. STh II–IIae q.35 a.3) Venial and mortal sins can be compared to sickness and death. While venial sin impairs full healthy activity of a person, mortal sin destroys the principle of spiritual life in him/her.
Robert Thieme
Thieme believed contemporary Christianity has superimposed a number of false actions on the Gospel message. Consequently, at least every Sunday, he would emphasize what did not need to be done for salvation: 
Thieme held that these actions, while some of them might be commendable from the human viewpoint, are an intrusion on faith. Faith is the absence of merit, and no human good of any form is acceptable to God for salvation. God extends the invitation to salvation, not the other way around. The Greek verb "metanoeo", translated "repent" in the Bible, when used in connection with salvation, means to change one's mind about Christ and believe in him at the point of Gospel hearing. At that point, the grace of God does everything necessary to make faith effectual for salvation. The only personal sin that results in eternal condemnation is to die without having personally believed in Jesus Christ as Savior. God solved the sin problem, and made an issue of individual volition. God knows the thoughts of every individual, and is not constrained by geographical isolation or linguistic barrier in his dissemination of the salvation message to those who desire a relationship with him. Water baptism and legitimate church activities are post-salvation functions of the believer, not prerequisites for salvation. 
Thieme categorized the Christian's life into three phases: the moment of salvation, the post-salvation life of the believer on Earth, and the believer in eternity. These distinctions allow the proper interpretation of verses pertaining to salvation (e.g. Acts 16:31, Eph. 2:8-9, Gen. 15:6), and verses pertaining to the post-salvation function of the believer (e.g. Jas. 2:17), so as not to obscure the simplicity of faith alone in Christ alone for salvation.
Ten Commandments
In Gospel of Barnabas, Jesus stated that idolatry is the greatest sin as it divests a man fully of faith, and hence of God. In his time, Idolatry is not only worshipping statues of wood or stone; but also statues of flesh. All which a man loves, for which he leaves everything else but that, is his god, thus the glutton and drunkard has for his idol his own flesh, the fornicator has for his idol the harlot and the greedy has for his idol silver and gold, and so the same for every other sinner.
Jewish views on sin
The generic Hebrew word for any kind of sin is "avera" (literally: transgression). Based on verses in the Hebrew Bible, Judaism describes three levels of sin. There are three categories of a person who commits an avera. The first one is someone who does an avera intentionally, or "B'mezid." This is the most serious category. The second is one who did an avera by accident. This is called "B'shogeg," and while the person is still responsible for their action it is considered less serious. The third category is someone who is a "Tinok Shenishba", which is a person who was raised in an environment that was assimilated or non-Jewish, and is not aware of the proper Jewish laws, or halacha. This person is not held accountable for his or her actions.
Al-Mu'minoon
Verses 5 through to 7 of this Surah says ""And who guard their modesty; Save from their wives or the (slaves) that their right hands possess, for then they are not blameworthy, But whoso craveth beyond that, such are transgressors". Zina (extramarital sex) is one of the major sins in Islam concerning which stern warnings have been issued in the Qur'an as well as authentic "aḥadīth" attributed to Muhammad. In Surah 17:32, God says "…come not near to Zina. Verily, it is Fahishah (immoral sin) and an evil way." The Qur'an also says that Homosexuality too is "Haraam" (sinful) and it is against the natural inclination which God has placed in man, whereby the male is inclined towards female and vice versa. In an authentic hadith from the Tirmidhi collection, Muhammad is reported to have said: ""There is nothing I fear for my Ummah more than the deed of the people of Lot."".
God in Islam
Tawhid constitutes the foremost article of the Muslim profession. The deification or worship of anyone or anything other than God (shirk) is the biggest sin in Islam. The entirety of the Islamic teaching rests on the principle of Tawhid.
Confession (religion)
Within confession, the sinner must confess both to God and to those persons wronged by the sin. Confession may also be required to an authorized priesthood leader, such as a bishop, branch president, stake president, or mission president. Although there is no definitive list of sins that require confession to a priesthood leader, "adultery, fornication, other sexual transgressions and deviancies, and sins of a comparable seriousness" are included, as is intentional and repeated use of pornography. Depending on the seriousness of the sin, the priesthood leader may counsel the sinner to submit to the authority of a disciplinary council, but does not have the authority to forgive sin, which can come only from God. The confession to the priesthood leader must be held in strict confidence unless the confessor grants permission to disclose it to the disciplinary council. The LDS Church rejects the belief that confession is all that is required to secure repentance from God.
John Chrysostom
He describes homosexuality as the worst of sins, greater than murder. He asserts that punishment will be found in hell for such transgressors, and that women can be guilty of the sin as much as men (although the former disrupt the patriarchal hierarchy through such an act). Chrysostom argues that the male passive partner has effectively renounced his manhood and become a woman – such an individual deserves to be "driven out and stoned". Chrysostom was particularly influential in shaping early Christian thought that same-sex desire was an evil that ultimately resulted in social injustice – altering the traditional interpretation of Sodom as a place of inhospitality, to one where the sexual transgressions of the Sodomites became paramount. Allen describes the sermon as the "climax and consummation of homophobia in the late classical world".
LGBT clergy in Christianity
The Presbyterian Church in America (PCA), the second-largest Presbyterian denomination in the United States, adheres to what they perceive as the biblical stance on homosexuality, affirming that "the act of homosexuality is a sin according to God's Word." Therefore, a practicing homosexual continuing in this sin would not be a fit candidate for ordination or membership in the Presbyterian Church in America.
Violence against LGBT people
Other contemporary Islamic views are that the ″crime of homosexuality is one of the greatest of crimes, the worst of sins and the most abhorrent of deeds″. Homosexuality is considered the 11th major sin in Islam, in the days of the companions of Muhammad, a slave boy was once forgiven for killing his master who sodomized him.
Sin
In a religious context, sin is an act of transgression against divine law. In Islamic ethics, Muslims see sin as anything that goes against the commands of Allah (God). Judaism regards the violation of any of the 613 commandments as a sin.
Christian views on sin
Original sin, also called ancestral sin, is the Christian doctrine of humanity's state of sin resulting from the fall of man, stemming from Adam's rebellion in Eden, namely the sin of disobedience in consuming from the tree of knowledge of good and evil. This condition has been characterized in many ways, ranging from something as insignificant as a slight deficiency, or a tendency toward sin yet without collective guilt, referred to as a "sin nature", to something as drastic as total depravity or automatic guilt of all humans through collective guilt.
Vanity
In many religions, vanity, in its modern sense, is considered a form of self-idolatry in which one likens oneself to the greatness of God for the sake of one's own image, and thereby becomes separated and perhaps in time divorced from the Divine grace of God. In Christian teachings, "vanity" is an example of pride, one of the seven deadly sins. Also, in the Bahai Faith, Baha'u'llah uses the term 'vain imaginings'.
Original sin
Original sin, also called ancestral sin, is a Christian belief in the state of sin in which humanity has existed since the fall of man, stemming from Adam and Eve's rebellion in Eden, namely the sin of disobedience in consuming the forbidden fruit from the tree of the knowledge of good and evil. This condition has been characterized in many ways, ranging from something as insignificant as a slight deficiency, or a tendency toward sin yet without collective guilt, referred to as a "sin nature", to something as drastic as total depravity or automatic guilt of all humans through collective guilt.
Religion and abortion
There is scholarly disagreement on how early Christians felt about abortion, and no explicit prohibition of abortion in either the "Old Testament" or "New Testament" books of the Christian Bible. Some scholars have concluded that early Christians took a nuanced stance on what is now called abortion, and that at different times, and in separate places, early Christians have taken different stances. Other scholars have concluded that early Christians considered abortion a sin at all stages; although there is disagreement over their thoughts on what type of sin it was and how grave a sin it was held to be, it was seen as at least as grave as sexual immorality. Some early Christians believed that the embryo did not have a soul from conception, and consequently, opinion was divided as to whether or not early abortion was murder or ethically equivalent to murder.
Mark 3
Jesus also makes the claim that "all sins" can be forgiven, except for an eternal sin, such as blasphemy against the Holy Spirit (). Mark inserts his own explanation as to why Jesus said this, stating "He said this because they were saying, "He has an evil spirit." (), thus Jesus according to Mark is saying that accusing him of using Satan for his power is in effect calling the work of God evil and failing to see the work of God in Jesus' actions. The parallels in and and the Gospel of Thomas 44 call this the unforgivable sin. Unforgivable sins are also listed in Hebrews and as well as 1 John . There is also a possible link with 1 Corinthians . 
His first answer to the charge, that a "house divided" cannot stand, has become a common piece of wisdom, the most famous modern example is Lincoln's use of this phrase during the 1858 senatorial election campaign against Stephen Douglas. Lincoln used the metaphor of a "house divided" to describe the situation of the United States on the eve of the Civil War.
Ben M. Bogard
In his debate with Church of Christ theologian Joseph Sale Warlick, from John 10:27-30, Bogard argued that a Christian who falls into sinful behavior still retains eternal security because of the sacrificial death of Jesus Christ on the cross and subsequent Resurrection, which are greater than an individual's imperfection. Bogard's critics countered that his view of eternal security conflicts with Ezekiel 33:13: if one "trusts to his righteousness, and commit iniquity, none of his righteous deeds shall be remembered; but in his iniquity that he hath committed, therein shall he die." This verse addresses placing trust in one's individual righteousness instead of sole faith in redemption from Christ. Bogard maintained that the blood of the crucified Christ exonerates the sinner whose salvation is assured at the time of repentance.
Persecution of Christians
These persecutions culminated with the reign of Diocletian and Galerius at the end of the third century and the beginning of the 4th century. The Great Persecution is considered the largest. Beginning with a series of four edicts banning Christian practices and ordering the imprisonment of Christian clergy, the persecution intensified until all Christians in the empire were commanded to sacrifice to the Roman gods or face immediate execution. According to legend, one of the martyrs during the Diocletian persecution was Saint George, a Roman soldier who loudly renounced the Emperor's edict, and in front of his fellow soldiers and tribunes claimed to be a Christian by declaring his worship of Jesus Christ. Though Diocletian zealously persecuted Christians in the Eastern part of the empire, his co-emperors in the West did not follow the edicts so Christians in Gaul, Spain, and Britannia were virtually unmolested.
Great Apostasy
In Christianity, the term Great Apostasy is derived from the Second Epistle to the Thessalonians, in which the Apostle Paul informs the Christians of Thessalonica that a great apostasy must occur before the return of Christ, when "the Man of Sin is revealed, the Son of Destruction" (chapter ). As no such thing had yet occurred, Paul says that Christ cannot have returned yet.
Christian perfection
Wesley did not, however, believe in an absolute "sinless" perfection, and he repudiated those who taught that Christians could achieve such a state. Wesley defined sin as conscious, voluntary transgression of known divine law. Involuntary transgressions (such as those arising from ignorance, error, and evil tempers), according to Wesley, were not properly called sins. Therefore, regenerated Christians would continue to be guilty of involuntary transgressions and would need to practice regular confession. Furthermore, Christians continued to face temptation, and Wesley acknowledged that it was possible for a regenerated Christian to commit voluntary sin (if, in the words of Noble, the Christian ceased "actively trusting in God through Christ and living in the divine presence"), which would also necessitate confession of sin.
Ethics in religion
Christian ethics in general has tended to stress the need for love, grace, mercy, and forgiveness because of sin. With divine assistance, the Christian is called to become increasingly virtuous in both thought and deed, see also the Evangelical counsels. Conversely, the Christian is also called to abstain from vice.
Guilt (emotion)
Guilt in the Christian Bible is not merely an emotional state but is a legal state of deserving punishment. The Hebrew Bible does not have a unique word for guilt, but uses a single word to signify: "sin, the guilt of it, the punishment due unto it, and a sacrifice for it." The Greek New Testament uses a word for guilt that means "standing exposed to judgment for sin" (e. g., Romans 3:19). In what Christians call the "Old Testament", Christians believe the Bible teaches that, through sacrifice, one's sins can be forgiven (Judaism categorically rejects this idea, holding that forgiveness of sin is exclusively through repentance, and the role of sacrifices was for atonement of sins committed by accident or ignorance ). The New Testament says that this forgiveness is given as written in 1 Corinthians 15:3–4: "3 For what I received I passed on to you as of first importance: that Christ died for our sins according to the Scriptures, for that he was buried, that he was raised on the third day according to the Scriptures." Some believe that the Old and New Testaments have differing opinions on the expiation of guilt because the Old Testaments were subject to the Age of Law and the New Testaments replace the Age of Law with the now current Age of Grace. However, both in the Old Testament and the New Testament salvation was granted based on God's grace and forgiveness (Gen 6:8; 19:19; Exo 33:12–17; 34:6–7). Animal sacrifices were only a symbol of the future sacrifice of Jesus Christ (Heb 10:1–4; 9–12). The whole world is guilty before God for abandoning him and his ways (Rom 3:19). In Jesus Christ, God took upon himself the sins of the world and died on the cross to pay our debt (Rom 6:23). Those who repent and accept the sacrifice of Jesus Christ for their sins, will be redeemed by God and thus not guilty before him. They will be granted eternal life which will take effect when Jesus comes the second time (1 Thess 4:13–18). In contrast to surrounding nations which addressed their guilt with human sacrifice, the Israeli authors of the Bible called that an abomination (1 Kings 11:7, Jer 32:35). The Bible agrees with pagan cultures that guilt creates a cost that someone must pay (Heb 9:22). (This assumption was expressed in the previous section, "Defences": "Guilty people punish themselves if they have no opportunity to compensate the transgression that caused them to feel guilty. It was found that self-punishment did not occur if people had an opportunity to compensate the victim of their transgression.") But unlike pagan deities who demanded it be paid by humans, God, according to the Bible, loved us enough to pay it Himself, as a good father would, while calling us His "children" and calling Himself our "father" (Mat 5:45).
Pliny the Younger on Christians
Neither Pliny nor Trajan mentions the crime that Christians had committed, except for being a Christian; and other historical sources do not provide a simple answer to what that crime could be, but most likely due to the stubborn refusal of Christians to worship Roman gods; making them appear as objecting to Roman rule.
Ten Commandments
The Ten Commandments concern matters of fundamental importance in Judaism and Christianity: the greatest obligation (to worship only God), the greatest injury to a person (murder), the greatest injury to family bonds (adultery), the greatest injury to commerce and law (bearing false witness), the greatest inter-generational obligation (honour to parents), the greatest obligation to community (truthfulness), the greatest injury to moveable property (theft).
Christian views on sin
Mortal sins, which are any severe and intentional actions that directly disobey God, are often confused with the seven deadly sins, which are pride, envy, wrath, sloth, greed, gluttony, and lust. They are not, however, the same. The seven deadly sins are called "deadly" because they might lead another to commit other sins. Some forms of the seven deadly sins (i.e. debilitating one's health because of their love of food) can constitute as grave matter, while others may just be venal (i.e. over-eating).
Religious views on masturbation
Another American, the puritanical C. Matthew McMahon, argues, "... if any form of sin is a product of lust, then it is an evil and wicked action. If a man masturbates while watching a sensual movie, then he has sinned. When masturbation grows out of a sense of this need for physical release due to unclean thoughts, it is sin. This is easily understood and biblically undeniable... Self-love, turning to lust, is at the heart of masturbation.. Instead, the Christian man must set in motion an attitude of holiness and purity, instead of uncleanness and defilement. When he does this, he then “practices what he preaches.” Though he says that holiness is right and good, he has to live that way as well. The question arises and must be answered “Is masturbation itself condemned? ... Is it, in and of itself, a sin? I am biblically persuaded that masturbation... can only be achieved through lust..."
Lust
St. Thomas Aquinas defines the sin of Lust in questions 153 and 154 of his Summa Theologica. Aquinas says the sin of lust is of "voluptuous emotions," and makes the point that sexual pleasures, "unloosen the human spirit," and set aside right reason (Pg.191). Aquinas restricts lust's subject matter to physical desires specifically arising from sexual acts, but Aquinas does not assume all sex-acts are sinful. Sex is not a sin in marriage, because sex is the only way for humans to reproduce. If sex is used naturally and the end purpose is reproduction there is no sin. Aquinas says, "if the end be good and if what is done is well-adapted to that, then no sin is present," (Pg.193). However, sex simply for the sake of pleasure is lustful and therefore, a sin. A man who uses his body for lechery wrongs the Lord.
Christian views on poverty and wealth
Jesus counsels his followers to remove from their lives those things which cause them to sin, saying "If your hand causes you to sin, cut it off. It is better for you to enter life maimed than to go with two hands into hell, where the fire never goes out." . In order to remove the desire for wealth and material possessions as an obstacle to faith, some Christians have taken vows of poverty. Christianity has a long tradition of voluntary poverty which is manifested in the form of asceticism, charity and almsgiving.
Kahan argues that Christianity is unique because it sparked the beginning of a phenomenon which he calls the "Great Renunciation" in which "millions of people would renounce sex and money in God's name."
Seven deadly sins
Pope Gregory combined this with "tristitia" into sloth for his list. When Thomas Aquinas described "acedia" in his interpretation of the list, he described it as an "uneasiness of the mind", being a progenitor for lesser sins such as restlessness and instability. Dante refined this definition further, describing acedia as the "failure to love God with all one's heart, all one's mind and all one's soul"; to him it was the "middle sin", the only one characterised by an absence or insufficiency of love. Some scholars have said that the ultimate form of acedia was despair which leads to suicide.
Tawhid
Greater Shirk consists of the above-mentioned deeds. A person commits lesser shirk (Shirk-al-Asghar) or hidden polytheism when he claims to believe in God but his thoughts and actions do not reflect his belief. There are also minor forms of Shirk, they must be avoided as well; these include committing a good deed to show off, making an oath in the name of anyone except God. Within Islam, shirk is an unforgivable crime; God may forgive any sin if one dies in that state except for committing shirk, repentance is required for its forgiveness.
Sloth (deadly sin)
Sloth is one of the seven capital sins. It is the most difficult sin to define, and to credit as sin, since it refers to a peculiar jumble of notions, dating from antiquity and including mental, spiritual, pathological, and physical states. One definition is: a habitual disinclination to exertion, or laziness.
Gluttony
In Christianity, it is considered a sin if the excessive desire for food causes it to be withheld from the needy. Some Christian denominations consider gluttony one of the seven deadly sins.
Sin
Sins between people are considered much more severe in Judaism than sins between man and God. Yom Kippur, the main day of repentance in Judaism, can atone for sins between man and God, but not for sins between man and his fellow, that is until he has appeased his friend. Eleazar ben Azariah derived [this from the verse]: "From all your sins before God you shall be cleansed" (Book of Leviticus, 16:30) – for sins between man and God Yom Kippur atones, but for sins between man and his fellow Yom Kippur does not atone until he appeases his fellow.
Laziness
One of the Catholic seven deadly sins is sloth, which is often defined as spiritual and/or physical apathy or laziness. Sloth is discouraged in (), 2 Thessalonians, and associated with wickedness in one of the parables of Jesus in the "Gospel of Matthew" (). In the Wisdom books of "Proverbs" and "Ecclesiastes", it is stated that laziness can lead to poverty (, ). According to Peter Binsfeld's "Binsfeld's Classification of Demons", Belphegor is thought to be its chief demon.
Christianity and Judaism
In both religions, offenses against the will of God are called sin. These sins can be thoughts, words, or deeds.
Christianity and Judaism
In Christianity, forgiveness by God is promised to the repentant even though the wronged party has not forgiven the offender: "If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness." (1 John 1:9 ) Jesus, however, requires his disciples to forgive others if they want to be forgiven themselves. Matthew 6:14,15, which follows the Lord's Prayer, says "For if you forgive men when they sin against you, your heavenly Father will also forgive you. But if you do not forgive men their sins, your Father will not forgive your sins." Forgiveness is not an option to a Christian, rather one must forgive to be a Christian.
Christian views on sin
Mortal sins are sins of grave (serious) matter, where the sinner performs the act with full knowledge and deliberate consent. (cf. CCC 1857)
Murder
In Islam according to the Qur'an, one of the greatest sins is to kill a human being who has committed no fault. "For that cause We decreed for the Children of Israel that whosoever killeth a human being for other than manslaughter or corruption in the earth, it shall be as if he had killed all mankind, and whoso saveth the life of one, it shall be as if he had saved the life of all mankind." "And those who cry not unto any other god along with Allah, nor take the life which Allah hath forbidden save in (course of) justice, nor commit adultery – and whoso doeth this shall pay the penalty."
Christianity and Judaism
Hebrew has several words for sin, each with its own specific meaning. The word "pesha", or "trespass", means a sin done out of rebelliousness. The word "aveira" means "transgression". And the word "avone", or "iniquity", means a sin done out of moral failing. The word most commonly translated simply as "sin", "het", literally means "to go astray". Just as Jewish law, "halakha" provides the proper "way" (or path) to live, sin involves straying from that path. Judaism teaches that humans are born with free will, and morally neutral, with both a "yetzer hatov", (literally, "the good inclination", in some views, a tendency towards goodness, in others, a tendency towards having a productive life and a tendency to be concerned with others) and a "yetzer hara", (literally "the evil inclination", in some views, a tendency towards evil, and in others, a tendency towards base or animal behavior and a tendency to be selfish). In Judaism all human beings are believed to have free will and can choose the path in life that they will take. It does not teach that choosing good is impossible—only at times more difficult. There is almost always a "way back" if a person wills it. (Although texts mention certain categories for whom the way back will be exceedingly hard, such as the slanderer, the habitual gossip, and the malicious person)
Love of money
In Jewish and Christian tradition, the love of money is condemned as a sin primarily based on texts such as Ecclesiastes 5:10 and 1 Timothy 6:10. The Jewish and Christian condemnation relates to avarice and greed rather than money itself. The Jewish and Christian texts (scriptures) are full of parables and use easy to understand subjects, such as money, to convey the actual message, there are further parallels in Solon and Aristotle, and Massinissa—who ascribed love of money to Hannibal and the Carthaginians.. Avarice is one of the Seven deadly sins in the Jewish and Christian classifications of vices (sins).
Donny Pauling
As a Christian, he believes that pornography is a sin against God and nature. However, he stated “One of the things that I like to tell people who are struggling with an addiction to pornography, or just about any other thing in their life, is that it’s really true that there’s nothing you could do that would change the fact that God loves you and wants to redeem you...It’s kind of like a parent who is watching their toddler learn to walk. And the toddler might fall down several times a day, but there’s never a good parent that ever says, ‘this walking thing isn’t for you. You should probably stay down there on the floor.’ But yet, some of us want to think that God’s that way and that our sin separates us from Him to such an extreme that He would never redeem us. But that’s not true. There’s nothing that we could do that would change the fact that when we turn to Him, and we ask Him to help us stand back up, He’s right there, willing to pick us up.”
Original sin
In Swedenborgianism, exegesis of the first 11 chapters of Genesis from "The First Church", has a view that Adam is not an individual person. Rather, he is a symbolic representation of the "Most Ancient Church", having a more direct contact with heaven than all other successive churches. Swedenborg's view of original sin is referred to as "hereditary evil", which passes from generation to generation. It cannot be completely abolished by an individual man, but can be tempered when someone reforms their own life, and are thus held accountable only for their own sins.
Damnation
In most forms of Western Christian belief, damnation to hell is what humanity deserves for its sins. Catholic and many Protestant denominations hold that human sin is the product of the fall of man of Adam and Eve in the book of Genesis. In some Christian denominations, only the sins that the Ten Commandments describe cause damnation, but others apply more strict terms. The reasons for being damned have varied widely through the centuries, with little consistency between different forms of Christianity (i.e., Catholic or Protestant). "Sins" ranging from murder to dancing have been said to lead to damnation.
Christian denominations have differing views on soteriology, but a mainstream view is that believers can only escape damnation by salvation from Jesus Christ.
Mortal sin
Some mortal sins cause automatic excommunication by the very deed itself, for example renunciation of faith and religion, known as apostasy, desecration of the Eucharistic species, and "a completed abortion". Those mortal sins are so serious that the Church through law has made them crimes. The Church forbids the excommunicated from receiving any sacrament (not just the Eucharist) and also severely restricts the person's participation in other Church liturgical acts and offices. A repentant excommunicated person may talk to a priest, usually in a confessional, about their excommunication to arrange for the remission. Remission cannot be denied to someone who has truly repented their actions and has also made suitable reparation for damages and scandal or at least has seriously promised to do so. However, even if excommunicated, a Catholic who has not been juridically absolved is still, due to the irrevocable nature of baptism, a member of the Catholic Church, albeit their communion with the Christ and the Church is gravely impaired. "Perpetual penalties cannot be imposed or declared by decree." However, "the following are expiatory penalties which can affect an offender either perpetually..."
Martha Wall
I have come to see that buying toys or ice cream or dog food is not sin. The sin lies in permitting Christians to remain victims of a warped sense of values that is impoverishing their own lives and robbing them of a great inheritance [in Heaven]... It is sin to allow earnest young Christians to plan mediocre lives around a materialistic ideal without challenging them to battle. We sin if we do not offer to lead the charge! God has sent us [missionaries] into a stirring conflict, one that should stir response in the blood of every Christian...God holds us responsible for advance!
Excommunication
In the more grievous or recalcitrant cases, excommunication becomes a disciplinary option. Excommunication is generally reserved for what are seen as the most serious sins, including committing serious crimes such as murder, child abuse, and incest; committing adultery; involvement in or teaching of polygamy; involvement in homosexual conduct; apostasy; participation in an abortion; teaching false doctrine; or openly criticizing church leaders. A 2006 revision to the "Handbook" states that formally joining another church constitutes apostasy and is an excommunicable offense; however, merely attending another church does not constitute apostasy.
Christian views on sin
The first reference to "sin" as a noun is of ""sin" is crouching at your door; it desires to have you, but you must rule over it” waiting to be mastered by Cain, a form of literary theriomorphism. 
The first use of the verb is God appears to Abimelech "in the dream, “Yes, I know you did this with a clear conscience, and so I have kept you from "sinning" against me. That is why I did not let you touch her.”" in Genesis 20:3. Isaiah announced the consequences: "But your iniquities have separated you from your God; your sins have hidden his face from you, so that he will not hear. For your hands are stained with blood, your fingers with guilt. Your lips have spoken falsely, and your tongue mutters wicked things" — a separation between God and man, and unrequited worshipping.
The New Church (Swedenborgian)
Remission of sins is their removal after repentance. The New Church differs from older Christian churches on this point. "The belief that the passion of the cross was redemption itself is a fundamental error of the church; and that error, together with the error concerning three Divine persons from eternity, has perverted the whole church, so that nothing spiritual is left in it." The crucifixion was the last temptation endured by Jesus.
Sin of omission
Paul the Apostle refers to this sin directly when he states "For I do not do the good I want ..." (Romans ).
James the brother of Jesus more exactly defines this sin when he states, "Whoever knows the right thing to do and fails to do it, for him it is sin." (James )
Christianity and Judaism
Catholicism categorizes sins into various groups. A wounding of the relationship with God is often called venial sin; a complete rupture of the relationship with God is often called mortal sin. Without salvation from sin (see below), a person's separation from God is permanent, causing such a person to enter Hell in the afterlife. Both the Catholic Church and the Orthodox Church define sin more or less as a "macula", a spiritual stain or uncleanliness that constitutes damage to man's image and likeness of God.
Chinese views on sin
The concept of "sin; offense against god" is a long-standing hamartiological problem for Christianity in China. Uhalley and Wu (2001:71-72) described it as a "notorious crux in Christian-Confucian dialogue"; "The central issues here are the doctrines of sin as an offense against God, original sin, and redemption, which are, for Christians, revealed doctrines. But all are absent from, rather than contrary to, Confucian values."
Tikkun HaKlali
Although the sin of wasted seed is considered the most serious of the violations of the Covenant, other sins also accomplish the same thing. Rebbe Nachman taught that one who earns his livelihood dishonestly also breaches the Covenant, as his craving for money can make him go so far as to rob his fellow man. The way one thinks, speaks and acts are also areas in which he can uphold or damage the Covenant.
Penance
Essential to the sacrament are acts both by the sinner (examination of conscience, contrition with a determination not to sin again, confession to a priest, and performance of some act to repair the damage caused by sin) and by the priest (determination of the act of reparation to be performed and absolution). among the penitent's acts contrition holds first place. Serious sins (mortal sins) must be confessed within at most a year and always before receiving Holy Communion, while confession of venial sins also is recommended.
Internal sin
Internal sin, in Christianity, is the idea that sin may be committed not only by outward deeds but also by the inner activity of the mind, quite apart from any external manifestation. Thought crimes were as old as heresy, but the Reformation's alarms received new emphasis at the Council of Trent (Session XIV, chapter. v). The session, while reiterating that all mortal sins must be confessed, singled out the unspoken ones that "sometimes more grievously wound the soul and are more dangerous than sins which are openly committed".
Criticism of Christianity
The idea of atonement for sin is criticized by Richard Dawkins on the grounds that the image of God as requiring the suffering and death of Jesus to effect reconciliation with humankind is immoral. The view is summarized by Dawkins: "if God wanted to forgive our sins, why not just forgive them? Who is God trying to impress?" Oxford theologian Alister McGrath maintains that Dawkins is "ignorant" of Christian theology, and therefore unable to engage religion and faith intelligently. He goes on to say that the atonement was necessary because of our flawed human nature, which made it impossible for us to save ourselves, and that it expresses God's love for us by removing the sin that stands in the way of our reconciliation with God. Responding to the criticism that he is "ignorant" of theology, Dawkins asks, "Do you have to read up on leprechology before disbelieving in leprechauns?" and "[y]es, I have, of course, met this point before. It sounds superficially fair. But it presupposes that there is something in Christian theology to be ignorant about. The entire thrust of my position is that Christian theology is a non-subject." Dinesh D'Souza says that Dawkins' criticism "only makes sense if you assume Christians made the whole thing up." He goes on to say that Christians view it as a beautiful sacrifice, and that "through the extremity of Golgotha, Christ reconciles divine justice and divine mercy." Andrew Wilson argues that Dawkins misses the point of the atonement, which has nothing to do with masochism, but is based on the concepts of holiness, sin and grace.
Multilateral foreign policy of the Holy See
In parallel, the Holy See condemns the violation to the freedom of religion, specially when suffered by Christians: It is painful to think that in some areas of the world it is impossible to profess one’s religion freely except at the risk of life and personal liberty. In other areas we see more subtle and sophisticated forms of prejudice and hostility towards believers and religious symbols. At present, Christians are the religious group which suffers most from persecution on account of its faith. Many Christians experience daily affronts and often live in fear because of their pursuit of truth, their faith in Jesus Christ and their heartfelt plea for respect for religious freedom. This situation is unacceptable, since it represents an insult to God and to human dignity; furthermore, it is a threat to security and peace, and an obstacle to the achievement of authentic and integral human development.
Christian views on sin
Other Christian scholars understand sin to be fundamentally relational—a loss of love for the Christian God and an elevation of self-love ("concupiscence", in this sense), as was later propounded by Augustine in his debate with the Pelagians. As with the legal definition of sin, this definition also affects the understanding of Christian grace and salvation, which are thus viewed in relational terms.
Eternal sin
The Catholic Encyclopedia cites Matthew 12:22–32; Mark 3:22–30; Luke 12:10 (cf. 11:14–23) and defines "the unforgivable sin"—or sin against the Holy Ghost—as follows: ″... to sin against the Holy Ghost is to confound Him with the spirit of evil, it is to deny, from pure malice, the Divine character of works manifestly Divine.″ The article further states that "sin against the Son of Man" may be forgiven because it is committed against the human person of Christ, which veils the Divine with a "humble and lowly appearance," and therefore such sin is excusable because it is committed through "man's ignorance and misunderstanding."
Human rights in ISIL-controlled territory
Iraqi Christians, the majority being the Chaldean Christians of Northern Iraq, have also been targeted by ISIL. The group tells Christians they must either convert to Islam, pay a fine, or face execution. ISIL has also taken Qaraqosh, Iraq's largest Christian city. Christians who fled the city reported summary executions and mass beheadings. Some have also been kidnapped and held for ransom. Others have been publicly whipped for refusing to convert to Islam. Many Christians have been displaced and have fled their villages to escape ISIL. The group has also systematically destroyed Christian churches and shrines. ISIL fighters have destroyed and vandalized many Christian monuments, and they have taken down crosses from the tops of churches, replacing them with ISIL flags. They've marked Christian homes with an Arabic "N" which stands for "Nasrane", a word used by Muslims to describe followers of the Christian faith.
Christian theology
In Eastern Christianity, sin is viewed in terms of its effects on relationships, both among people and between people and God. Sin is seen as the refusal to follow God's plan, and the desire to be like God and thus in direct opposition to him (see the account of Adam and Eve in the Book of Genesis). To sin is to want control of one's destiny in opposition to the will of God,
to do some rigid beliefs.
Zoophilia
In Part II of his Summa Theologica, medieval philosopher Thomas Aquinas ranked various "unnatural vices" (sex acts resulting in "venereal pleasure" rather than procreation) by degrees of sinfulness, concluding that "the most grievous is the sin of bestiality." Some Christian theologians extend Matthew's view that even having thoughts of adultery is sinful to imply that thoughts of committing bestial acts are likewise sinful.
Seven deadly sins
With Christianity, historic Christian denominations such as the Catholic Church and Protestant Churches, including the Lutheran Church, recognize seven virtues, which correspond inversely to each of the seven deadly sins. 
Confession is the act of admitting the commission of a sin to a priest, who in turn will forgive the person in the name (in the person) of Christ, give a penance to (partially) make up for the offense, and advise the person on what he or she should do afterwards.
Mortal sin
A mortal sin (), in Catholic theology, is a gravely sinful act, which can lead to damnation if a person does not repent of the sin before death. A sin is considered to be "mortal" when its quality is such that it leads to a separation of that person from God's saving grace. This type of sin should be distinguished from a venial sin that simply leads to a weakening of a person's relationship with God. Despite its gravity, a person can repent of having committed a mortal sin. Such repentance is the primary requisite for forgiveness and absolution. Teaching on absolution from serious sins has varied somewhat throughout history. The current Catholic teaching was formalized at the 16th century Council of Trent.
Adam
Christianity sees human nature as irrevocably stained by the sin of Adam. The idea is not found in Judaism (nor in Islam), and was introduced by the Apostle Paul, drawing on currents in Hellenistic Jewish thought which held that Adam's sin had introduced death and sin into the world. Sin, for Paul, was a power to which all humans are subject, but Christ's coming held out the means by which the righteous would be restored to the Paradise from which Adam's sin had banished mankind. He did not conceive of this original sin of Adam as being biologically transmitted or that later generations were to be punished for the deeds of a remote ancestor. It was Saint Augustine who took this step, locating sin itself in male semen: when Adam and Eve ate of the fruit they were ashamed and covered their genitals, identifying the place from which the first sin was passed on to all succeeding generations. Only Jesus Christ, who was not conceived by human semen, was free of the stain passed down from Adam. (Augustine's idea was based on the ancient world's ideas on biology, according to which male sperm contained the entire unborn baby, the mother's womb being no more than a nurturing chamber in which it grew.)
Apostasy in Christianity
The Epistle to the Hebrews is the classic text on the subject of apostasy in the New Testament. New Testament scholar Scot McKnight argues that the warning passages (2:1–4; 3:7–4:13; 5:11–6:12; 10:19–39; 12:1–29) should be read and interpreted "as an organic whole, each of which expresses four components of the author’s message." These four components are "(1) the subjects or audience in danger of committing the sin, (2) the sin that leads to (3) the exhortation, which if not followed, leads to (4) the consequences of that sin." McKnight concluded from his study that (1) the subjects of this letter were genuine "believers, persons who . . . had converted to Jesus Christ,” (2) The sin "is apostasy, a deliberate and public act of deconfessing Jesus Christ, a rejection of God's Spirit, and a refusal to submit to God and His will," (3) the exhortation is "to a persevering faithfulness to God and his revelation of the new covenant in Jesus Christ," (4) the consequences involve "eternal damnation if a person does not persevere in the faith." B. J. Oropeza concludes that apostasy threatens the community in Hebrews on two fronts: mistreatment by outsiders (persecution) and malaise involving reluctance to listen to godly exhortation.
Christian views on sin
Venial sins are sins which do not meet the conditions for mortal sins. The act of committing a venial sin does not cut off the sinner from God's grace, as the sinner has not rejected God. However, venial sins do injure the relationship between the sinner and God, and as such, must be reconciled to God, either through the Sacrament of Reconciliation or receiving the Eucharist (after proper contrition fulfilled).
History of the Catholic Church and homosexuality
In the "Summa Theologica", Thomas Aquinas stated that "the unnatural vice" is the greatest of the sins of lust. In his "Summa contra Gentiles", traditionally dated to 1264, he argued against what he called "the error of those who say that there is no more sin in the emission of the semen than in the ejection of other superfluous products from the body" by saying that, after murder, which destroys an existing human being, disordinate emission of semen to the preclusion of generating a human being seems to come second.
Christian views on sin
Another group of four or five sins distinguished by the Church are the sins that cry to heaven: murder, sodomy, (oppression of a people,) oppression of the weak and defrauding the laborer.
Christian theology
In Russian variant of Eastern Christianity, sin sometimes is regarded as any mistake made by people in their life. From this point of view every person is sinful because every person makes mistakes during his life. When person accuses others in sins he always must remember that he is also sinner and so he must have mercy for others remembering that God is also merciful to him and to all humanity.
Catholic theology of sexuality
The Catholic Church disapproves of masturbation. Thomas Aquinas, one of the most prominent Doctors of the Catholic Church, wrote that masturbation was an "unnatural vice" which is a species of lust", but that it is a less serious form than bestiality, which is "the most serious", and than sodomy, which is the next most serious: "By procuring pollution [i.e., ejaculation apart from intercourse], without any copulation, for the sake of venereal pleasure [...] pertains to the sin of 'uncleanness' which some call 'effeminacy' [Latin: "mollitiem", lit. 'softness, unmanliness']."
Christianity
With around 2.4 billion adherents, split into three main branches of Catholic, Protestant and Eastern Orthodox, Christianity is the world's largest religion. The Christian share of the world's population has stood at around 33% for the last hundred years, which means that one in three persons on earth are Christians. This masks a major shift in the demographics of Christianity; large increases in the developing world have been accompanied by substantial declines in the developed world, mainly in Europe and North America. According to a 2015 Pew Research Center study, within the next four decades, Christians will remain the world's largest religion; and by 2050, the Christian population is expected to exceed 3 billion.
Thou shalt not bear false witness against thy neighbour
To keep “a clear conscience toward God and toward men”(Acts 24:16), Christians must follow Christ's example “to bear witness to the truth.”(John 18:37) The Christian is not to “be ashamed then of testifying to our Lord.”(2 Timothy 1:8) In situations that require witness to the faith, the Christian must profess it without equivocation. Christian witness to the Gospel and the obligations that flow from it are an act of justice that establishes the truth or makes it known. Catholic teaching regards martyrdom as the supreme witness given to the truth of the faith: it means bearing witness even unto death.
Christ's disciples have "put on the new man, created after the likeness of God in true righteousness and holiness."(Ephesians 4:24) By "putting away falsehood," they are to "put away all malice and all guile and insincerity and envy and all slander." (Ephesians 4:25, 1 Peter 2:1)
Public statements contrary to the truth take on a particular gravity. In court it becomes false witness. (Proverbs 19:9) False statements under oath are perjury. Acts such as these contribute to condemnation of the innocent, exoneration of the guilty, or the increased punishment of the accused. (Proverbs 18:5) These are great sins, because they gravely compromise the exercise of justice and the fairness of judicial decisions.
LGBT rights opposition
Passages in the Old Testament that prohibit man "lie with mankind as with womankind" and the story of Sodom and Gomorrah have historically been interpreted as condemning sodomy. Several Pauline passages have also been cited against male and female homosexuality. Christians who take a conservative position on homosexuality endorse this reading of these passages in the belief that God is against same-sex sexual activity, while Christians who take a liberal position believe that these same passages refer to more specific situations, such as rape or abuse, and not homosexuality. The largest Christian body, the Catholic Church, condemns homosexual acts as "gravely sinful" and "intrinsically disordered". The second-largest Christian body, the Eastern Orthodox Church, also condemns homosexual behaviour, as do most denominations of Protestantism.
Caelestius
Caelestius also went much further than Pelagius in stating that the sin of Adam, as chronicled in the Biblical Book of Genesis had only harmed himself, and not all of humanity, as Augustine had taught in his writings and sermons (Pelagius has been accused of starting this teaching, but in fact he anathematized the opinions of Caelestius at the Synod of Lydda in 415 A.D., as well as in a letter to the pope shortly thereafter). In several books on the topic, Augustine also argued that Pelagius and Caelestius neglected to take God's divine grace into account. Augustine believed Adam's sin ("Fall") in the Garden of Eden had caused human beings to lose the ability to not sin. (""non posse non peccare"" in Latin) and therefore, all good deeds done by Christians come from them being enabled by God to do good. In contrast, Pelagius believed that God gave the power of free will to all men, not just Christians, in such a way that no one was forced into sin (Augustine even wrote certain remarks that seemed to imply that any such forced action would not in fact be sinful). Caelestius again appears to have gone beyond this and denied that Christian goodness is due to grace, on the grounds that this would imply that if any Christian sinned, it was because God's grace had failed; once again at the Synod of Lydda Pelagius anathematized this position (although he stated that he did not mean to indicate whether they were Caelestius' opinions or not).