All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
In principle it is permissible for a Muslim man to marry a woman from the people of the book if she is chaste. Allaah Says when mentioning the women whom we are allowed to marry (what means): {…and chaste women from those who were given the scripture (Jews and Christians) before you…}[Quran 5:5]. Her will to stay on her religion is not an obstacle that prevents you from marrying her. As regards going to the church to conduct the ceremony of marriage, this is not permissible, as it is most likely that there are some religious prohibitions which a Muslim is not permitted to witness like rites by which they associate partners to Allaah, the presence of intoxicants, musical instruments and the like.
In principle it is her non-Muslim guardian who would conduct her marriage and he is permitted to appoint whoever he wants as an agent to act on his behalf, be him a priest or anyone else. However, it is not permissible to conduct the marriage without the consent of the guardian as his consent is a condition for the validity of marriage. The Prophet said: "Any woman who gets married without the consent of her guardian, her marriage is invalid, her marriage is invalid, her marriage is invalid." [Abu Daawood]. However, if this woman does not have a guardian, or that her guardian refuses to marry her off without any sound reason, then the bishops may conduct the marriage contract for her.
Our advice is that you should not marry a woman from the people of the book as there are many disadvantages in marrying her. Imaam Maalik said: "In my view, it is disliked to marry women from the people of the book, a Christian or a Jew, but I do not prohibit it. That is because she eats pork and drinks intoxicants, and her husband would kiss her in her mouth, and she will give birth to children and bring them up according to her religion, feeds them what is forbidden, and gives them to drink intoxicants."
On the contrary, a Muslim should be keen to marry a pious Muslim woman who would help him in his religious and worldly matters, and preserve his honour and dignity (i.e. not commit illegal sexual intercourse) when he is absent. Allaah Says (what means): {Therefore the righteous women are devoutly obedient (to Allaah and to their husbands), and guard in [the husband’s] absence what Allaah orders them to guard.}[Quran 4:34].
For more benefit, please refer to Fatwa 84724.
Allaah Knows best.