God is faithful to forgive us of our sin, if we confess it  -  1 John 1:9

If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.

Because of Christ, when we sin, if we confess it, God cleanses us from it. We must confess all of our sins – sins of commission, sins of omission, sins of thought, sins of action, secret sins, and public sins. Only when we confess all of our sin, do we receive cleansing from God.