Job 19:4 (ESV)

4 And even if it be true that I have erred, my error remains with myself.

Job knows that he is not perfect (see Job 7:20–21; Job 13:26; Job 14:4). Yet there is a difference between error (which in Scripture refers to sin that is committed unknowingly) and deliberate wickedness. Job’s friends have accused him of the worst degree of wickedness.