1 John 1:10
First John 1:5–10 opens the main topic of John’s letter. God is entirely goodness and truth, and those who follow God cannot also follow evil and falsehood. John offers a pattern of “if” statements, comparing each to the truth. In particular, John mentions those who claim to be entirely free from sin, or to have never sinned. Such a belief is literally the opposite of the gospel. No person is sinless other than Jesus Christ.
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“1 John 1:10” Bibleref.com
1 John 1:9-10
9 If we confess our sins, he is faithful and righteous to forgive us the sins, and to cleanse us from all unrighteousness. 10 If we say that we haven’t sinned, we make him a liar, and his word is not in us.