If we say that we have no sin, we deceive ourselves, and the truth is not in us.
If we say that we have no sin: John enters into another hypothetical, yet very applicable, case. He begins by saying that "If we" (meaning "anybody"), say "we have no sin," we deceive ourselves. Since there is no article before "sin," the denial here refers to the possession of sinfulness in the life. It is a claim to inherent perfection with no need for cleansing. In verse 10, John will deal with the denial of specific sins in daily life. As we have already noted, the Cerinthian Gnostics were making the claim of sinlessness. They had no sin because law and sin did not affect them nor apply to the spirit of man. Some today claim to live "above sin" or in sinless perfection. What should our attitude be toward people who make such claims? Please observe John’s reaction to such a notion in the next statement.