The Act of Contrition is a prayer to express our sorrow for committing sin and desire for God’s mercy, forgiveness, and help in our fight against sin. In the Sacrament of Penance and Reconciliation we make an Act of Contrition with a prayer expressing 1) sorry for sin, 2) hatred for sin, and 3) the resolution not to sin again. Then the priest absolves of our sin in the name of the Father, Son, and Holy Spirit.
This prayer can also be said at any point after making a brief examination of conscience to identify the sins that have pulled us away from God.
The Act of Contrition
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.
Another variation of the Act of Contrition is:
O my God, I am heartily sorry for having offended Thee, and I detest all my sins because of Thy just punishments, but most of all because they offend Thee, my God, Who art all-good and deserving of all my love. I firmly resolve, with the help of Thy grace, to sin no more and to avoid the near occasions of sin.