Christianity and Judaism
In contrast to the Jewish view of being morally balanced, Original Sin refers to the idea that the sin of Adam and Eve's disobedience (sin "at the origin") has passed on a spiritual heritage, so to speak. Christians teach that human beings inherit a corrupted or damaged human nature in which the tendency to do bad is greater than it would have been otherwise, so much so that human nature would not be capable now of participating in the afterlife with God. This is not a matter of being "guilty" of anything; each person is only personally guilty of their own actual sins. However, this understanding of original sin is what lies behind the Christian emphasis on the need for spiritual salvation from a spiritual Saviour, who can forgive and set aside sin even though humans are not inherently pure and worthy of such salvation. Paul the Apostle in Romans and I Corinthians placed special emphasis on this doctrine, and stressed that belief in Jesus would allow Christians to overcome death and attain salvation in the hereafter.
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']."