In the Catholic Church, catholics are told to go to confession as much as possible, in order to confess their sins to a priest or any of higher rank in the church.
After confession, the piest absolves the sins and instructs that 5 'Our Fathers', 5 'Hail Marys', and 5 'Glory be to the Fathers'. (The number of prayers to be said varies with how many sins that were confessed.)
Now, if I were to ask, "What is the purpose of confession?" The response would most certainly be: "To be absolved of our sins."
FACT: "...then neither do I condemn you." Jesus declared. "Go and leave your life of sin." - John 8:11
Here Our Lord Jesus instructs a woman, who has lead a life of sin, to leave her sinful life, because she has been forgiven.
Then if I were to ask: "Since you have confessed all of your sins to the priest, and have been absolved of them all by him, why do you still think yourselves guilty of sin?"
Let us look at the last sentence of a 'Hail Mary', which you are instructed to say immediately after confession.
"....Pray for us sinners now and at the hour of our death. Amen."
I underlined the words,'us sinners', because it includes the person saying the prayer.
Therefore if you include yourself to be a sinner
OF WHAT USE IS THE CONFESSION YOU HAVE JUST BEEN TO?