The Sacrament of Penance and Reconciliation
The Catholic Sacrament of Reconciliation (also known as Confession, Penance, or Penance and Reconciliation) has three elements: conversion, confession and celebration. In it we find God's unconditional forgiveness; as a result we are called to forgive others.
"Those who approach the sacrament of Penance obtain pardon from God's mercy for the offense committed against him, and are, at the same time, reconciled with the Church which they have wounded by their sins and which by charity, by example, and by prayer labors for their conversion."
Act of Contrition
O my God, I am heartly sorry for having offended you, and I detest all my sins, because I dread the loss of heaven and the pains of hell; but most of all because they offend you, my God, who are all good and deserving of all my love. I firmly resolve, with the help of your grace, to confess my sins, to do penance, and to amend my life. Amen.