If we say that we have not sinned, we make him a liar, and his word is not in us.
If we say that we have not sinned, we make him a liar, and his word is not in us. (7) A repeat of the former verse, in which he condemned all of sin without exception: so much so that if any man persuade himself otherwise, he does as much as in him lies, make the word of God himself useless and to no effect...
To deny our sin is to deceive ourselves and exclude the truth from us entirely. The Christian religion is the religion of sinners; Christian life is continued repentance and mortification of sin. Denying sin does not merely deceive us, it calls God a liar and dishonors His testimony against the world's sin.
AI summary
Commenting on 1 John 1:8-10
Verse 10. If we say that we have not sinned. In times that are past. Some perhaps might be disposed to say this; and as the apostle is careful to guard every point, he here states that if a man should take the ground that his past life had been wholly upright, it would prove that he had no true religion.