If anyone says, “I know Him,” but does not keep His commandments, he is a liar, and the truth is not in him.
4 He that saith, I know him How does he prove that they are liars who boast that they have faith without piety? even by the contrary effect; for he has already said, that the knowledge of God is efficacious. For God is not known by a naked imagination, since he reveals himself inwardly to our hearts by the Spirit.
These verses may seem to relate to the seventh verse of the former chapter, between which and these verses there occurred an incidental discourse concerning the believer's duty and relief in case of sin, occasioned by the mention of one of the believer's privileges - his being cleansed from sin by the Mediator's blood.
Commenting on 1 John 2:3-6
He that saith I know him,.... God or Christ, as the Gnostics did, who pretended to great, even perfect, knowledge of divine things: and keepeth not his commandments; which the above persons had no regard to, and as many who profess great light and knowledge in our days show no concern for: is a liar; he contradicts what he says, and gives the lie to...