Why won't God just overlook sin if Jesus already paid for it on the cross?
God will not overlook sin because He hates it. Even though sin has been paid for and forgiven through the death on the cross, God is never going to wink at sin; He cannot. Sin still must be dealt with through repentance and getting right with God, as the Corinthian situation illustrates.
Les teaches that God hates sin and will not wink at it, even though He has paid for it and forgiven it because of His death on the cross. He cannot wink at sin. In the Corinthian situation, the guilty party was to be dealt with severely, turned over to the power of Satan so his flesh could be touched, unless he turned around in repentance and got right with God. Les says this is a perfect picture of how you and I even today have to deal with sin. Paul adds that all profited from the situation: Paul, the congregation, and the guilty party. Everything got squared away, and they were comforted. Paul felt as they felt, and Titus's spirit was refreshed by the Corinthians' obedience, received with fear and trembling.