Sheikh Sâlih al-Sultân, professor at al-Imâm University, al-Qasîm branch
There can be no doubt that what you have done is wrong and contrary to Islamic Law. When a Muslim man marries a Christian woman, it is under the understanding that their children will be raised as Muslims.
What you have to do now is call your son to Islam in the best and kindest possible manner. Take him to the Islamic centers in your locality and arrange to find someone who can convince him of the truth. It is your duty to call your wife to Islam as well in a kindly manner.
I advise you to move from your place of residence to an Islamic area if you can.
Source: Islam Today