“But if we confess our sins to him, he is faithful and just to forgive us our sins and to cleanse us from all wickedness.” (bold is my emphasis) 1 John 1:9
The first key to overcoming sin is knowing ourselves and our enemy. The second step to overcoming sin is confession, the third key that I think is most important in overcoming sin is knowing who our God is and the power He has to deliver us.
When we sin, we must be quick to go to Christ in repentance and prayer. If we have wronged someone as a part of our sin, then we must ask for forgiveness from that person. These can be some of the most difficult things to do. In the story of King David in the Old Testament, he committed a great sin when he committed adultery with Bathsheba, the sin grew as he tried to cover it up and eventually was guilty of causing the death of her husband in the process (2 Samuel 11-12). When the prophet, Nathan, confronted David about what he had done, his response was, “I have sinned against the LORD.” David didn’t try and make a bunch of excuses, he immediately repented. David understood that God knows our hearts, and He loves us in spite of knowing it all. God does not bless us for our decisions, he knows they are faulty, but He does bless us for our confession and acknowledge meant of our sin, that is why confession is so important. Christ has the power, He carried our sin to the Christ and only He alone can wash us clean.
He lifted me out of the slimy pit,
out of the mud and mire;
he set my feet on a rock
and gave me a firm place to stand.