Confession

I have been reading a fiction book about St. Columba of Ireland, Iona and Lindisfarne. He is continually suffering from guilt of past sins. He keeps doing penance for them, including sleeping on a stone pillow.
He visits an aged Monk named Mungo. Here is a portion of that conversation:
{Mungo: "The Grace of God covers all sin and guilt. All. You have only to give it to Him, You have given Him the sin for forgiving."
Columba thought.
"It is to my thinking that by your continuing to do penance you are refusing to surrender all to God's grace. You must put all behind you and go forth in the freedom of His love."}
I was thinking about this short conversation and came to wonder how many of us really don't "give it up" even after confessing the sin. But we either continue to commit the same sin, or carry the guilt we should not carry.
Paula