The liar (o pseusth). The liar (with the article) par excellence. Rhetorical question to sharpen the point made already about lying in Acts 1:6Acts 1:10 ; Acts 2:4Acts 2:21 . See Acts 5:5 for a like rhetorical question. But (ei mh). Except, if not. That denieth that Jesus is the Christ (o arnoumeno oti Ihsou ouk estin o Cristo). Common Greek idiom for ouk to appear after arneomai like redundant mh in Luke 20:27 ; Hebrews 12:19 . The old Latin retains non here as old English did (Shakespeare, Comedy of Errors IV. ii. 7, "He denied you had in him no right"). The Cerinthian Gnostics denied the identity of the man Jesus and Christ (an aeon, they held) like the modern Jesus or Christ controversy. This is the antichrist (outo estin o anticristo). The one just mentioned, Cerinthus himself in particular. Even he that denieth the Father and the Son (o arnoumeno ton patera kai ton uion). This is the inevitable logic of such a rejection of the Son of God. Jesus had himself said this very same thing ( John 5:23 ).