One difficult human reality is that we sin. We harm ourselves, others, relationships and God our Father with our sinful and evil actions. However, our God is loving and will always pour out His mercy and forgiveness; we need only seek to reconcile ourselves with Him and with our community.
Our sins are forgiven by God. As Catholics we believe that Christ gave the power to his Apostles (and in turn, His priests) to reconcile sinners with God and the Church: “Whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.” (Mt 16:19) The priest, acting in persona Christi, listens to the sins of the contrite person, gives counsel and penance. The priest then absolves the sinner of their sins, and sends them on their way, to sin no more.
In order to receive absolution, the sinner must be truly sorry, confess all their sins to the priest, and perform the penance given to him.