Catholics believe that the Holy Mother Church gives birth in the Sacrament of Baptism, nourishes in the Holy Eucharist, helps Catholics grow in Confirmation, and heals in the Sacrament of Penance.This was really brought home to me the last time I went to Confession. The priest was giving me several steps to do ... he kept repeating, "to heal your wounded soul." I realized that I had been thinking in terms of having broken a rule but not of the consequence to me. It was very soothing to think of my "wounded soul" being restored.
Medicine and therapy can heal a wounded body, but Catholics believe that only God's grace can heal a wounded soul. That's why Jesus left the Sacrament of Penance to heal our spiritual wounds, which we call sin.
Often, people think of sin only as breaking God's laws. Sure, stealing, lying, and murdering break some of the Ten Commandments and are considered sinful. But Catholics believe that God said, "Thou shalt not," because he knew these sinful actions would wound spiritually.
Catholics think of sin like a bacteria or virus to the soul. When a person lies, cheats, steals, or murders, it's like being infected with millions of deadly germs. The longer the infection is left untreated, the more it spreads and worsens. It wounds and can even kill the life of grace that enables entry into heaven.
Just as tumors are benign or malignant, Catholics believe that sins are venial or mortal. In other words, some sins aren't considered as serious as others and merely inflict a slight wound to the soul, but others are so intrinsically evil that they're considered deadly. They're called mortal sins, because they can kill grace.
The Sacrament of Penance (also known as the Sacrament of Reconciliation or Confession) is for spiritual healing. According to the Gospels, after the Resurrection, Jesus appeared to the apostles, breathed on them, and said, "Receive the Holy Spirit. Whose sins you shall forgive, they are forgiven them; whose sins you shall retain, they are retained," (John 20:22-23).
Because Jesus gave the apostles the power to forgive sins, he must have wanted them to use it. So the Sacrament of Penance has been the very will of Christ from day one.Catholicism for Dummies by John Trigilio