What is the ruling regarding a man marrying a Christian woman who later turns out to be an unbeliever in God? What is the fate of the children in terms of custody, financial support, and lineage? Is it permissible for him to remain with her in order to guide her to Islam?

Marriage to a Christian woman is permissible, but it carries certain risks, including: her influence on the children's faith and behavior, and the danger of the children remaining with her in case of separation. For this reason, jurists have disliked marriage to them except out of necessity. As for an atheist woman, marriage to her is not permissible. If one marries her unknowingly of her condition, he must separate from her immediately. The children are attributed to him, and her custody of them is forfeited due to her apostasy from Islam, and because Allah "will not grant the disbelievers any way [of superiority] over the believers." Children are born upon fitra (natural disposition), and their parents influence them. The children's maintenance is incumbent upon their father.