1 John 4:1 ASV

¹  Beloved, believe not every spirit, but prove the spirits, whether they are of God; because many false prophets are gone out into the world.

²  Hereby know ye the Spirit of God: every spirit that confesseth that Jesus Christ is come in the flesh is of God:

³  and every spirit that confesseth not Jesus is not of God: and this is the `spirit' of the antichrist, whereof ye have heard that it cometh; and now it is in the world already.