The Catholic Sacrament of Reconciliation (also known as 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.
When we sin, we deprive ourselves of God’s grace. And by doing so, we make it even easier to sin some more. The only way out of this downward cycle is to acknowledge our sins, to repent of them, and to ask God’s forgiveness. Then, in the Sacrament of Confession, grace can be restored to our souls, and we can once again resist sin.
What Is Required?
Three things are required of a penitent in order to receive the sacrament worthily:
He must be contrite—or, in other words, sorry for his sins.
He must confess those sins fully, in kind and in number.
He must be willing to do penance and make amends for his sins.