Confession of Sins

The Council of Trent teaches us that the complete confession of sins was also instituted by the Lord and is by divine law necessary for all who have fallen after Baptism…For it is clear that without knowledge of the case priests could not exercise this judgment, nor could they observe equity in the imposition of penances if the penitents declared their sins only in general not specifically and in particular.

Thus it follows that all mortal sins, of which penitents after a diligent self-examination are conscious, must be recounted by them in confession, though they may be most secret and may have been committed only against the last two precepts of the Decalogue; for these sins sometimes wound souls more grievously and are more dangerous than those which are committed openly…when Christ’s faithful strive to confess all sins that occur to their memory, they undoubtedly place all of them before the divine mercy for pardon. But those who fail to do so and knowingly withhold some, place nothing before the divine goodness for remission.

One is not obliged to confess doubtful mortal sins. If, in making a confession, one deliberately conceals a mortal sin, one lies to the Holy Ghost and thereby commits a grave sacrilege. The sin of deception is more serious than one which God punishes by death itself because it is perpetrated within the sacrament. No sins are forgiven, not even those which were confessed.

The Council of Trent teaches clearly that venial sins are proper matter for the sacrament of Penance. However, they are optional or free matter. One may confess them, but is not obliged to do so. As regards venial sins, by which we are not excluded from the grace of God and into which we fall more frequently, it is right and profitable, and implies no presumption whatever, to declare them in confession, as can be seen from the practice of devout people; yet, they may be omitted without guilt and can be expiated by many other remedies, for example, through prayer, fasting, almsgiving, or other forms of penance and works of charity.

We must make an integral confession of all mortal sins according to species and approximate number. According to species means that we must confess clearly what particular kind of sin one has committed. It is not enough to say “I have committed sins of impurity and injustice.” We have to be specific. We must say I have lied, stolen, cheated, etc.