Jesus instituted this sacrament, knowing that we need continued conversion. Even after having received the Sacrament of Baptism there still remains in us concupiscence, a tendency towards sin. This tendency is not sin. As a matter of fact, the person, who struggles against these temptations, gains merit in the sight of God. Freely consenting to them is sin. However, only God can forgive sins. That is why Jesus gave this power to every validly ordained priest in his Church: "Whose sins you forgive are forgiven them, and whose sins you retain are retained." (John 20:21-23) By the power of God each priest forgives the sins he hears when he says the words of absolution.
To have a valid confession, there must be contrition, the confession of sins and satisfaction. There are two kinds of contrition. The most desirable is perfect contrition which arises purely from the love of God. Sufficient for a good confession is also Imperfect contrition which is regret coming form the loss of God and heaven. Understandably, either kind of sorrow must include a purpose of amendment, that is, the resolution to avoid sin and all occasions leading to sin.
The actual verbal confessing of sins to a priest must include all sins committed since a persons last good confession:
Confession to a priest is an essential part of the sacrament of Penance: "All mortal sins of which penitents after a diligent self-examination are conscious must be recounted by them in confession, even if they are most secret and have been committed against the last two precepts of the Decalogue; for these sins sometimes wound the soul more grievously and are more dangerous than those which are committed openly." (Catechism of the Catholic Church, no. 1456)
Because of heartfelt sorrow and sincerity, a person makes an honest examination of conscience. He sees the sins he has committed (particularly the serious ones) and takes responsibility for them. One should never be afraid of confessing any sin or feel embarrassed. The only way to heal the soul is to reveal all the wounds. Jesus is there with his love and mercy.
Satisfaction means doing our best to remedy the damage caused by our sins. Every sin causes some disorder. First, it offends God, Also, it often wrongs another person. Thirdly, it harms the one committing the sin. So, we have the obligation to try to make up for this injury usually through prayer but also by good works.
More on this subject next week.