Is it permissible for a Muslim man married to a Christian woman, with whom he has three children, to prevent her from teaching their children the Christian religion, and would anything contrary to that befall him?

The children follow the religion of their Muslim father. The father must raise them according to Islam and prevent the mother from converting them to Christianity, in accordance with the Almighty's saying: "O you who have believed, protect yourselves and your families from a Fire." He should invite the mother to Islam, or distance the children from her if he fears their corruption, and provide a righteous environment for them to teach them the Quran and the rulings of the religion.