1 John 4:3 in the King James Version
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.
Context
2 By this you know the Spirit of God: every spirit who confesses that Jesus Christ has come in the flesh is of God,
3 and every spirit who doesn’t confess that Jesus Christ has come in the flesh is not of God; and this is the spirit of the Antichrist, of whom you have heard that it comes. Now it is in the world already.
4 You are of God, little children, and have overcome them, because greater is he who is in you than he who is in the world.