1Jo 1:7 "...the blood of Jesus Christ His Son cleanses us from all sin."
One time the Devil tempted Martin Luther and made him remember all his sins. Sins from his boyhood, sins from his youth, sins from his manhood up to that time. He then told Luther: "Look at you! You are so filthy!"
Luther replied: "Is that all it? Write some more!"
The Devil replied: "That's all. There is nothing more to write."
Luther then replied: "Then write across all of my sins 'the blood of Jesus Christ His Son cleanses us from all sin."
You see, it's not our good works, our religious achievement, our good character etc. that can cleanse all our sins. It is only the blood of the Lord Jesus Christ shed on Calvary that can cleanse it away. Trust in what He did on the cross for you.