On the evening of his resurrection from the dead, Jesus appeared to his Apostles and gave them the power to forgive all human sins. Breathing upon them, He said, "Receive the Holy Spirit. If you forgive anyone’s sins, they are forgiven. If you retain anyone’s sins, they are retained." (John 20:22-23) Through the Sacrament of Holy Orders, bishops and priests of the Roman Catholic Church receive the ability from Christ himself to forgive sins. It is exercised in the Sacrament of Reconciliation, also known as the Sacrament of Penance or simply as "confession."
In order to receive the Sacrament of Reconciliation worthily, the penitent (the sinner) must be sorry for his or her sins. Contrition, perfect or imperfect, must include a firm purpose of amendment, that is, a solid resolution to avoid the sin committed as well as the persons, places and things that prompted you to commit the sin in the first place. Without this repentance, contrition is insincere and your confession in pointless.
When you come to Church to confess your sins, you should first examine your conscience. Review your life to see how you offended the good God since your last confession. The Church teaches that all mortal sins committed after Baptism must be confessed to a priest in order to be forgiven.
1. I am the Lord your God. You shall not have strange gods before me. Do I seek to love God with my whole heart and soul? Does He truly hold the first place in my life? Have I been involved with the occult or superstitious practices, i.e. fortune-telling? Have I ever received Holy Communion in the state of mortal sin? Have I told a lie in confession or deliberately withheld confessing a mortal sin? Do I pray regularly?
2. You shall not take the name of the Lord your God in vain. Have I insulted God’s holy name or used it carelessly or irreverently? Have I lied under oath?
3. Remember to keep holy the Lord’s Day. Have I missed Mass deliberately on Sunday, or on Holy Days of obligation? Do I try to keep Sunday as a day of rest, holy to the Lord?
4. Honor your father and your mother. Do I honor and obey my parents? Do I care for them in their old age? Did I disrespect my parents or superiors? Have I neglected my family responsibilities to spouse, children, or parents?
5. You shall not kill. Have I murdered or physically harmed anyone or attempted to do so? Have I had an abortion, used abortifacient contraceptives or encouraged anyone to do so? Have I abused drugs or alcohol? Have I sterilized myself in any way or encouraged anyone to do so? Did I participate in or approve of euthanasia or "mercy-killing"? Have I harbored hatred, anger or resentment in my heart towards anyone? Have I cursed anyone? Have I given scandal to anyone by my sins, thereby leading them to sin?
6. You shall not commit adultery. Have I been unfaithful to my marriage vows in action or thought? Have I practiced any form of contraception? Have I been engaged in premarital or extramarital sexual activity with a member of the opposite sex or the same sex? Have I masturbated? Have I indulged in pornographic material? Am I pure in my thoughts, words actions? Am I modest in dress? Am I involved in any inappropriate relationships?
7. You shall not steal. Have I taken what is not mine or helped others steal? Am I honest with my employer/employee? Do I gamble excessively thereby robbing my family of their needs? Do I seek to share what I have with the poor and needy?
8. You shall not bear false witness against your neighbor. Have I lied, gossiped or spoken behind anyone’s back? Have I ruined anyone’s good name? Do I reveal information that should be confidential? Am I sincere in my dealings with others or am I "two-faced"?
9. You shall not desire your neighbor’s wife. Am I envious of another’s spouse or family? Have I consented to impure thoughts? Do I try to control my imagination? Am I reckless and irresponsible in the literature I read, the movies I watch, the web sites I surf, the places I frequent?
10. You shall not desire your neighbor’s goods. Am I envious of the possessions of others? Am I resentful and bitter over my position in life?
After you confess your sins, listen to the advice the priest offers you. You may also seek his help and guidance. He will then give you a penance. He will ask you to either pray, fast or perform an act of charity. Finally, the priest will ask you to express your sorrow for the sins confessed in an Act of Contrition, and then, exercising the power of Christ, he will give you absolution.