1 John 2:19-22

These enemies of Christ were in our fellowship, but they left us. They never really belonged to us; if they had been a part of us, they would have stayed with us. But they left, and this shows that none of them really belonged to us. You have the gift that the Holy One gave you, so you all know the truth. I do not write to you because you do not know the truth but because you do know the truth. And you know that no lie comes from the truth. Who is the liar? It is the person who does not accept Jesus as the Christ. This is the enemy of Christ: the person who does not accept the Father and his Son.