"'Those who approach the sacrament of Penance obtain pardon from God's mercy for the offense committed against him, and are, at the same time, reconciled with the Church which they have wounded by their sins and which by charity, by example, and by prayer labors for their conversion'" (CCC, 357).
The forgiveness of sins committed after Baptism is granted through a specific sacrament known as the sacrament of conversion, confession, penance, or reconciliation. When a sinner commits sin, they wound God's honor and love, undermine their own dignity as a person called to be a son of God and harm the spiritual well-being of the Church.