Children, it is the last hour; and just as you have heard that the antichrist is coming, so now many antichrists have appeared. This is how we know it is the last hour. They went out from us, but they did not belong to us. For if they had belonged to us, they would have remained with us. But their departure made it clear that none of them belonged to us. You, however, have an anointing from the Holy One, and all of you know the truth. (I John 2:18-20)
Going to a "Christian" church, calling oneself a Christian, checking a box on a form that asks "Religion?" with Christian, doesn't make one a Christian.