1 John 4:3

and every spirit who does not confess Jesus is not of God, and this is the spirit of the Anti-Christ, of whom you have heard that it comes. Now it is in the world already.

And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world.