1 John 4:1-3

King James Version

4 Beloved, believe not every spirit, but try 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 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.