2:23Whosoever denieth the Son, the same hath not the Father: (but) he that acknowledgeth the Son hath the Father also.

4:2Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God:

4:3And 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.