Colossians 2:13 ...Paul teaches you that ALL your sin is gone, forgiven, remitted, redeemed, by Christ on the Cross.
Roman 4:8 Paul then confirms that God does not ever again, hold you accountable for your sin, in eternity.
He can't, as all your sin, ALL OF IT, Paul just told you is taken care of by Jesus on the Cross as the Blood Atonement.
So, your sin is gone, and when you are confessing and repenting of what is not being charged to you, you are wasting your Christian Life.
God does not re-clean you, every time you mess up and tell Him you are sorry.