The Prophet (peace and blessings of Allaah be upon him) did not marry Maariyah al-Qibtiyyah, rather she was his concubine. The Muqawqis, the ruler of Egypt, gave her as gift to him after the Treaty of al-Hudaybiyah.
It is permissible to have intercourse with a slave woman, even if she is not Muslim, because she is part of what one's right hand possesses, and Allaah has permitted what one's right hand possesses without stipulating that the slave woman be a Muslim. Allaah says (interpretation of the meaning):
And those who guard their chastity (i.e. private parts, from illegal sexual acts)
6. Except from their wives or (the slaves) that their right hands possess,.. for then, they are free from blame
With regard to marrying a Christian or Jewish woman, this is permissible according to the text of the Qur'aan. Allaah says (interpretation of the meaning):
Made lawful to you this day are At‑Tayyibaat [all kinds of Halaal (lawful) foods, which Allaah has made lawful (meat of slaughtered eatable animals, milk products, fats, vegetables and fruits)]. The food (slaughtered cattle, eatable animals) of the people of the Scripture (Jews and Christians) is lawful to you and yours is lawful to them. (Lawful to you in marriage) are chaste women from the believers and chaste women from those who were given the Scripture (Jews and Christians) before your time when you have given their due Mahr (bridal-money given by the husband to his wife at the time of marriage), desiring chastity (i.e. taking them in legal wedlock) not committing illegal sexual intercourse, nor taking them as girlfriends
Ibn al-Qayyim said:
It is permissible to marry a woman from the People of the Book. Allaah says (interpretation of the meaning):
(Lawful to you in marriage) are chaste [muhsan] women from the believers and chaste women from those who were given the Scripture (Jews and Christians) before your time
Muhsan here means chaste; the same word is also used in Soorat al-Nisa' to describe married women, who are forbidden in marriage to anyone else. And it was said that the chaste women to whom marriage is permitted is free women, so slave women from the People of the Book are not permissible. However, the first view is the one which is correct, for several reasonsâ¦
The point is that Allaah has permitted us to marry chaste women from among the People of the Book, and the companions of the Prophet (peace and blessings of Allaah be upon him) did that. Uthmaan married a Christian woman, as did Talhah ibn Ubayd-Allaah; and Hudhayfah married a Jewish woman.
Abd-Allaah ibn Ahmad said: I asked my father about a Muslim man who married a Christian or Jewish woman. He said: I do not like for him to do it, but if he does, then some of the companions of the Prophet (peace and blessings of Allaah be upon him) did that too.
Ahkaam Ahl al-Dhimmah, 2/794, 795.
Although we say that it is permissible, and we do not doubt that there is a clear text concerning that, nevertheless we do not think that a Muslim should marry a kitaabi woman (a woman of the people of the Book), for several reasons:
1 - One of the conditions of marriage to a kitaabi woman is that she should be chaste, but there are very few chaste women to be found in those environments.
2 - One of the conditions of marriage to a kitaabi woman is that the Muslim man should be in charge of the family. But what happens nowadays in that those who marry women from kaafir countries marry them under their laws, and there is a great deal of injustice in their systems. They do not recognize a Muslim's authority over his wife and children, and if the wife gets angry with her husband she will destroy his household and take the children away, with the support of the laws of her land and with the help of their embassies in most countries. It is no secret that the Muslim countries have no power to resist the pressure of those countries and their embassies.
3 - The Prophet (peace and blessings of Allaah be upon him) encouraged us to look for Muslim wives who are religiously committed. If a woman is Muslim but is not religiously committed and of good character, then the Muslim is not encouraged to marry her, because marriage is not simply the matter of physical enjoyment only, rather it is the matter of Allaah's rights and the spouse's rights, and preserving his household, his honour and his wealth, and bringing up his children. How can a man who marries a kitaabi woman be certain that his sons and daughters will be raised according to Islam when he is leaving them in the hands of this mother who does not believe in Allaah and associates others with Him?
Hence even though we say that it is permissible to marry a kitaabi woman, it is not encouraged and we do not advise it, because of the negative consequences that result from that. The wise Muslim should choose the best woman to bear his children and think in the long term about his children and their religious upbringing. He should not let his desire or worldly interests or transient outward beauty blind him to reality; true beauty is the beauty of religious commitment and good morals.
He should realize that if he forsakes these type of women for the sake of that which is better for his religious commitment and that of his children, Allaah will compensate him with something better, because Whoever gives up something for the sake of Allaah, Allaah will compensate him with something better than that, as the Prophet (peace and blessings of Allaah be upon him) told us, the one who speaks the truth and does not speak of his own whims and desires. Allaah is the source of strength and the One Who guides to the Straight Path.
See also the answer to question no. 2527
And Allaah knows best.
Reproduced from Islam QA