2:22Who is a liar but he that denieth that Jesus is the Christ? He is antichrist, that denieth the Father and the Son.

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

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.