I'm in a situation which is very hard, I'm married with American girl and in south of United State, she is pregnant and it seems that she is deciding that the child will be Christian, I don't know what to do I thought she will change her mind but she become more sticking to her belief.

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.

The children follow their Muslim father in regard to their religion. So, it is not permissible for you to be tolerant on this matter; rather you should prevent your wife from turning your children into Christians. You should do your best to nurture them to hold fast to Islamic religion. Allaah Says (which means): {O you who have believed, protect yourselves and your families from the Fire.}[Quran 66:6]. First, you should endeavour to call their mother to Islam so that she will help you in bringing them up according to Islamic principles, otherwise you should take them away from her if you fear that she will spoil them. Then, you should prepare for your children a righteous environment, a good company, teach them the Quran and help them to memorize it, and teach them Islamic rulings and principles.

Please refer to Fatwa 86405 on the ruling of residing in a non-Muslim country, and Fataawa 81758 and 84159 on marrying the People of the Book.  

Allaah Knows best.