Catholics believe that the Church heals in the Sacrament of Penance. The Sacrament of Penance (or Sacrament of Reconciliation or Confession) is for spiritual healing. Catholics believe Jesus left the Sacrament of Penance because only God’s grace can heal a wounded soul.
Penance helps Catholics atone for sins they’ve committed. Catholics think of sin like a bacteria or virus to the soul. When a person lies, cheats, steals, or murders, it’s like his soul is infected with millions of deadly germs. Sinning not only breaks God’s laws — the Ten Commandments, for example — but wounds the sinner spiritually.
Just as tumors are benign or malignant, Catholics believe that sins are venial or mortal. Venial sins inflict a slight wound to the soul, but other sins are so intrinsically evil that they’re considered deadly. They’re called mortal sins, because they can kill grace. The Church believes that mortal sins can’t be forgiven and the soul damns itself to hell without absolution from a priest.
The manner in which this sacrament is done has developed over time, but the basics have always remained:
Confession: You must confess all known mortal sins to a priest. You can confess all your sins, but start with any mortal sins.
The priest is bound by the most absolute secrecy and confidentiality known to humankind. Not even the Pope can get a priest to tell who went to him for confession or what was confessed. The priest must be willing to endure prison, torture, and death before violating the Seal of Confession, the secrecy of the sacrament.
Contrition: You must be sorry you committed the sins and resolve to do your best not to repeat them.
Penance: After you confess your sins, the priest gives you a penance to perform. A penance may be to do something nice for your enemy every day for a week. It may be to visit a nursing home or hospital one day a week for a month. It may be to donate time to a soup kitchen or clothing bank. It may involve any one of the corporal or spiritual works of mercy. Or it may be a set of prayers, such as saying the Our Father or the Hail Mary, a certain number of times.
Whatever the penance, it’s merely a token, because Catholics believe that the sacrifice of Christ on the cross is what made atonement for our sins. Your penance is for your benefit — to remind you that God comes first and you come last.
Absolution: The priest or bishop hearing your confession (deacons don’t have the power to celebrate this sacrament), offers forgiveness, saying a prayer that calls on God to give you absolution and peace.
Receiving the Eucharist with mortal sin on your soul is a sacrilege, which means using something sacred for an unworthy purpose. It’s disrespect for the sacrament and another mortal sin.