The Sacrament of Reconciliation
Many Catholics treasure the sacrament of Reconciliation. The peace of mind and soul which this sacrament imparts to us is one for which there is no substitute. It is a peace that flows from a certainty, rather than from an unsure hope, that our sins have been forgiven and that we are right with God.
Although many converts to the Catholic Church initially fear it, they quickly come to love the sacrament of Reconciliation once they get over their nameless fears—fears which come from a misconception of what the sacrament really is.
Confession, Penance & Reconciliation
The sacrament of Reconciliation is also known as Penance and Confession, among other names. (There is an explanation of some of these names in the Catechism's section on the sacrament of Reconciliation.)
Although often called Reconciliation in common usage, the term "penance" best describes the essential interior disposition required for this sacrament.
In fact, there is a virtue of penance. This is a supernatural virtue by which we are moved to detest our sins from a motive made known by faith, and with an accompanying purpose of offending God no more and of making satisfaction for our sins. In this sense the word "penance" is synonymous with "penitence" or "repentance."
Before the time of Christ the virtue of penance was the only means by which people's sins could be forgiven. Even today, for those outside the Church in good faith, not possessing the sacrament of Penance, it is the only means for forgiveness of sins.
The sacrament of Reconciliation is a sacrament in which the priest, as the agent of God, forgives sins committed after Baptism, when the sinner is heartily sorry for them, sincerely confesses them, and is willing to make satisfaction for them.
By his death on the Cross, Jesus Christ redeemed man from sin and from the consequences of his sin, especially from the eternal death that is sin's due.
So it is not surprising that on the very day he rose from the dead, Jesus instituted the sacrament by which men's sins could be forgiven.