A Robe of Righteousness.

"He made Jesus, who knew no sin, to become sin on our behalf, so we might become the righteousness of God in Jesus."
2 Corinthians 5:21

When I was first a Christian, every time I did something wrong I would feel terrible and guilty. I would be ashamed to even pray to God because I didn't think he would want to hear from someone like me. After a few days of feeling awful, I would ask God to forgive me until the next time it happened. It became a cycle in my relationship with Him.

Then I learned about how we are covered by Christ's robe of righteousness. When God looks at us, he sees Jesus. I learned God loved me no matter what I did and I could rest in his love.
"I will rejoice greatly in the Lord,
My soul will exult in my God;
For he has clothed me with garments of salvation,
He has wrapped me with a robe of righteousness..."
Isaiah 61:10

Now, when I sin, I know God loves me. I talk with him about my sin and ask him to keep me from doing it again. I then just leave it with him and don't worry any longer. Jesus told us not to worry about anything, and that includes our sins, mistakes and weaknesses. In fact, when we see we are weak it is then we can become strong.
"I am well content with weakness, with insults, with distress, with persecution, with difficulty, for Christ's sake; for when I am weak, then I am strong.
2 Corinthians 12:10