How can we reconcile between the permissibility of marriage to a Christian or Jewish woman and belief in al-wala’ wa’l-bara’?
Question

I was having a discussion with my brother about loving the people of the Book, and I said to him that this is not permissible, and it is not permissible to take them as friends or to congratulate them on their festivals, or even initiate greetings with them, and other kinds of love. But he argued back by saying that Allah has permitted us to marry their women, and Allah has created love and compassion between spouses.
I hope that you can give us a detailed answer that will reconcile between the belief in al-wala’ wa’l-bara’ (love and friendship towards believers versus disavowal of disbelievers), and the notion of love for a wife from the people of the Book (i.e. a Jewish or Christian woman). What are the conditions stipulated in sharee‘ah for marriage to a Jewish or Christian woman?
Praise be to Allah.Firstly:
We have previously explained the conditions that must be met by a Jewish or Christian woman in order for it to be permissible to marry her. Please see the answers to questions no. 95572 and 2527. 
Secondly: 
Generally speaking, love is of two types: spiritual love (that is based on ties of faith) and natural love (that is based on human inclinations and feelings). With regard to spiritual love, some types are obligatory and some are prohibited, and some types constitute shirk (association of others with Allah) – you may find a detailed discussion of that in the answer to question no. 276. 
With regard to natural love, this is that which is naturally inherent in man, such as love of cold drinks or love of wealth. That also includes love for parents, children and relatives. There is no reward for it in principle, but a person may be sinning if he goes to extremes in his love for these things at the expense of his religious commitment and going against the laws of his Lord, such as if he becomes a slave to money, or he gives precedence to obeying his father over obeying his Lord, and so on. 
Ibn al-Qayyim (may Allah have mercy on him) said: 
It is proven in as-Saheeh that the Prophet said: “No one of you truly believes until I am more beloved to him than his child and his father and all the people.” This hadith mentions three kinds of love, for love is either based on respect and veneration, such as love for one’s father; or it is based on compassion, affection and kindness, such as love for one’s child; or it is love that is motivated by kindness and aspirations of attaining perfection, such as love of people for one another. No person truly believes until his love for the Messenger (blessings and peace of Allah be upon him) is greater than all these kinds of love.
End quote from Jala’ al-Afhaam (1/391, 392) 
Part of natural love is that which exists between spouses, which dispels the confusion mentioned in the brother’s question. The existence of natural love between the spouses does not mean that one should overlook spiritual love that is based on religious ties. Therefore it is possible to dislike her in one way because she is following the wrong religion whilst loving her because she is one’s wife. It is possible to differentiate between these two matters, for a person is naturally inclined to have love for fathers, mothers, children and wives, yet at the same time it is not allowed to love the disbelievers who are hostile towards Islam, no matter how close they may be to one. Allah, may He be exalted, says (interpretation of the meaning):
“You (O Muhammad (blessings and peace of Allah be upon him)) will not find any people who believe in Allah and the Last Day, making friendship with those who oppose Allah and His Messenger (Muhammad (blessings and peace of Allah be upon him)), even though they were their fathers, or their sons, or their brothers, or their kindred (people). For such He has written Faith in their hearts, and strengthened them with Rooh (proofs, light and true guidance) from Himself. And We will admit them to Gardens (Paradise) under which rivers flow, to dwell therein (forever). Allah is pleased with them, and they with Him. They are the Party of Allah. Verily, it is the Party of Allah that will be the successful” [al-Mujaadilah 58:22]. 
One of the major principles of Islam is that no soul is burdened with more than it can bear. Hence it is possible to differentiate between the two types of love, that which occurs naturally and that which is prescribed in Islam; this is within a person’s capability. 
Allah, may He be exalted, has told us of how Ibraaheem (peace be upon him) and the believers who were with him resented their people who were disbelievers, even though among them were their families and relatives, and there was natural love among them. Allah, may He be exalted, says (interpretation of the meaning):
“Indeed there has been an excellent example for you in Ibrahim (Abraham) and those with him, when they said to their people: ‘Verily, we are free from you and whatever you worship besides Allah, we have rejected you, and there has started between us and you, hostility and hatred for ever, until you believe in Allah Alone’” [al-Mumtahinah 60:4]. 
Allah, may He be exalted, approved of the love of the Prophet (blessings and peace of Allah be upon him) for his paternal uncle Abu Taalib, despite the fact that he was a disbeliever, because that was natural love that was based on ties of kinship. 
Shaykh Saalih al-Fawzaan (may Allah preserve him) said: 
Allah revealed concerning Abu Taalib the words (interpretation of the meaning): “Verily! You (O Muhammad (blessings and peace of Allah be upon him)) guide not whom you love” [al-Qasas 28:56]. That is, you do not have the power to guide whomever you love among your relatives or your paternal uncle. What is meant by love here is natural love, not spiritual love, for it is not permissible to have spiritual love for a mushrik even if he is the closest of people to you. “You (O Muhammad (blessings and peace of Allah be upon him)) will not find any people who believe in Allah and the Last Day, making friendship with those who oppose Allah and His Messenger (Muhammad (blessings and peace of Allah be upon him)), even though they were their fathers, or their sons, or their brothers, or their kindred (people)” [al-Mujaadilah 58:22]. So spiritual love is not permissible in this case; as for natural love, that does not have anything to do with religious matters.
I‘aanah al-Mustafeed bi Sharh Kitaab at-Tawheed (1/356) 
All of that was summed up by Shaykh ‘Abd ar-Rahmaan al-Barraak (may Allah preserve him) in a wise answer concerning this issue. He said: 
There are two types of love: natural love, such as a man’s love for his wife, his child and his wealth; this is the type mentioned in the verse in which Allah, may He be exalted, says (interpretation of the meaning): “And among His Signs is this, that He created for you wives from among yourselves, that you may find repose in them, and He has put between you affection and mercy. Verily, in that are indeed signs for a people who reflect” [ar-Room 30:21]. (The other type is) spiritual love, such as love for Allah and His Messenger, and love for that which Allah and His Messenger love of deeds, words and people. 
Allah, may He be exalted, says (interpretation of the meaning): “…Allah will bring a people whom He will love and they will love Him…” [al-Maa’idah 5:54]. And the Prophet (blessings and peace of Allah be upon him) said: “The likeness of the believers in their mutual love, compassion and affection is that of the body…” 
There is not necessarily a connection between the two types of love, in the sense that natural love may exist alongside spiritual resentment, such as love for parents who are mushrikeen. One may resent them for the sake of Allah, but this is not contrary to love for them which is natural, because humans are created with the inclination to love their parents and relatives, as the Prophet (blessings and peace of Allah be upon him) loved his paternal uncle because he was a close relative, despite the fact that he was a disbeliever. Allah, may He be exalted, says (interpretation of the meaning): “Verily! You (O Muhammad (blessings and peace of Allah be upon him)) guide not whom you love” [al-Qasas 28:56]. 
Another example of this type of love is: love for a wife who is one of the People of the Book. It is obligatory to resent her in a spiritual sense because of her disbelief, but that does not rule out loving her in the sense of that love which exists between a man and his wife. So she is beloved in one way and resented in another. This is something that occurs frequently. Natural dislike or resentment may be combined with spiritual love, as in the case of jihad: it may be disliked naturally, but loved because Allah enjoins it and because of the positive consequences that result from it in this world and the hereafter. Allah, may He be exalted, says (interpretation of the meaning): “Jihad (fighting in Allah’s Cause) is ordained for you (Muslims) though you dislike it, and it may be that you dislike a thing which is good for you and that you like a thing which is bad for you. Allah knows but you do not know” [al-Baqarah 2:216]. 
Another example of this type is the Muslim’s love for his fellow Muslim who has wronged him; he loves him for the sake of Allah but he resents him because of his mistreatment of him. In fact both natural love and natural resentment may coexist, as in the case of bitter medicine: the patient hates it because it is bitter but he takes it because of the benefits he hopes to gain from it. 
Similarly, spiritual love may coexist with spiritual resentment, as in the case of the Muslim who is an evildoer; he is loved for the sake of what he has of faith, but he is resented for the sin that he commits. 
The wise man is the one who regulates his love and resentment in accordance with Islamic teachings and reason, far removed from whims and desires. And Allah knows best.
End quote. 
And Allah knows best.