usccb.org/liturgy/penance.shtm
Straight from the US Council of Catholic Bishops
lGoing to Confession
Many people have avoided celebrating the Sacrament of Penance, sometimes for years at a time, because they “don’t know what to do.” The following brief explanation is intended for a person who has not been to confession in some time. It explains how the first form of the Sacrament of Penance may be celebrated. The person who is going to confession is called a “penitent” because he or she wishes to do penance and to turn away from sin.1
Preparation
Before going to confession, the penitent compares his or her life with the Ten Commandments, the Beatitudes, and the example of Christ and then prays to God for forgiveness.
Going to Confession
The priest welcomes the penitent and then both make the sign of the cross, saying, “In the name of the Father, and of the Son, and of the Holy Spirit, Amen.” Next the priest briefly urges the penitent to have confidence in God.
If the penitent is unknown to the priest, it is proper for the penitent to indicate his or her state of life, the time of the last confession, difficulties in leading the Christian life, and anything else that may help the confessor in exercising his ministry.
The Word of God
Then the priest or the penitent may read a passage from the Bible. Suggested passages include Ezekiel 11:19-20, Matthew 6:14-15, Mark 1:14-15, Romans 5:8-9, Ephesians 5:1-2, 1 John 1:6-7 and 9, or another text from Sacred Scripture.
Confession of Sins and the Act of Penance
The penitent then confesses his or her sins. If necessary, the priest should help the penitent to make a complete confession and to have sincere sorrow for sins against God. The sorrow a penitent feels for his or her sins is known as contrition and must include a resolve to sin no more and to avoid all future occasions of sin.2 Through confession of sins, the penitent "looks squarely at the sins he is guilty of, takes responsibility for them, and thereby opens himself again to God and to the communion of the Church in order to make a new future possible."3
The priest then offers suitable advice to help the penitent begin a new life and, when appropriate, leads him or her to resolve to make appropriate restitution for the harm he or she has caused others. The priest imposes an act of penance or satisfaction on the penitent. The penance corresponds to the seriousness and nature of the sins and may suitably take the form of prayer, self-denial, and especially service to one’s neighbor and works of mercy. Such a “penance” serves not only to make up for the past but also to help the penitent to begin a new life and provides the penitent with an antidote to weakness.
The Prayer of the Penitent or Act of Contrition
After this, the penitent prays a prayer expressing sorrow for his or her sins and resolving not to sin again. A card with several examples of the prayer may be provided in the confessional. The penitent may recite the prayer by heart or read it.
Here is one example of the Prayer of the Penitent:
My God,
I am sorry for my sins with all my heart.
In choosing to do wrong
and failing to do good,
I have sinned against you
whom I should love above all things.
I firmly intend, with your help,
to do penance,
to sin no more,
and to avoid whatever leads me to sin.
Our Savior Jesus Christ
suffered and died for us.
In his name, my God, have mercy.4
Absolution by the Priest
Following this prayer, the priest extends his hands, or at least his right hand, over the head of the penitent and pronounces the formula of absolution. As he says the final words he makes the sign of the cross over the head of the penitent:
God, the Father of mercies,
through the death and resurrection of his Son
has reconciled the world to himself
and sent the Holy Spirit among us
for the forgiveness of sins;
through the ministry of the Church
may God give you pardon and peace,
and I absolve you from your sins
in the name of the Father, and of the Son, +
and of the Holy Spirit.5
The penitent answers, “Amen.”
Proclamation of Praise
After receiving pardon for his or her sins, the penitent praises the mercy of God and gives him thanks in a short invocation taken from Scripture, such as “Rejoice in the Lord and sing for joy, friends of God” (Ps 32:1-7, 10-11), “The Lord has remembered his mercy” (Lk 1:46-55), or “Blessed be God who chose us in Christ” (Eph 1:3-10).6
Dismissal of the Penitent
Then the priest tells the penitent to go in peace. The penitent continues his or her conversion and expresses it by a life renewed according to the Gospel and more and more steeped in the love of God, for “love covers over a multitude of sins” (1 Pt 4:8).
