By this you know the Spirit of God: every spirit that confesses that Jesus Christ came in the flesh, is from God:

and whatever spirit confesses not that Jesus Christ came in the flesh, is not from God: and this is the spirit of antichrist, of which you have heard that it comes, and is now already in the world.

This is he that came by water and by blood, Jesus the Christ; not by water only, but by water and by blood: and it is the Spirit that testifies, because the Spirit is truth.

And we know that the Son of God has come, and has given us understanding, that we may know him that is true: and we are in him that is true, in his Son Jesus Christ. This is the true God, and life eternal. Little children, keep yourselves from idols.