Penance is that sacrament designed to address the problem of post-baptismal sins. According to the CC, the new life received in baptism "has not abolished the frailty and weakness of human nature, nor the inclination to sin that tradition calls concupiscence, which remains in the baptized such that with the help of the grace of Christ they may prove themselves in the struggle of Christian life" (CC, 1426).
This sacrament exists for those "who, since Baptism, have fallen into grave sin, and have thus lost their baptismal grace and wounded ecclesial communion. It is to them that the sacrament of Penance offers a new possibility to convert and to recover the grace of justification" (CC, 1446).
This sacrament goes by any of four names: (1) the sacrament of conversion; (2) the sacrament of confession; (3) the sacrament of Reconciliation; and (4) the sacrament of penance, because, notes Kreeft, "we must not only internally turn from our sins but also externally do something to repair the damage our sins have done" (341). Sin does more than offend God. It brings disorder and damage and harm to others:
"Many sins wrong our neighbor. One must do what is possible in order to repair the harm (e.g., return stolen goods, restore the reputation of someone slandered, pay compensation for injuries). Simply justice requires as much. But sin also injures and weakens the sinner himself, as well as his relationships with God and neighbor. Absolution takes away sin, but it does not remedy all the disorders sin has caused. Raised up from sin, the sinner must still recover his full spiritual health by doing something more to make amends for the sin: he must 'make satisfaction for' or 'expiate' his sins. This satisfaction is also called 'penance'" (CC, 1459).
Whereas only God can forgive sin, "by virtue of his divine authority he gives this power to men to exercise in his name" (CC, 1441). God has "entrusted the exercise of the power of absolution to the apostolic ministry which he charged with the 'ministry of reconciliation'" (CC, 1442). This is how Rome interprets John 20:23 - 'If you forgive the sins of any, their sins have been forgiven them; if you retain the sins of any, they have been retained.' The Catechism contends that "the words bind and loose [or 'forgive' and 'retain'] mean: whomever you exclude from your communion, will be excluded from communion with God; whomever you receive anew into your communion, God will welcome back into his. Reconciliation with the Church is inseparable from reconciliation with God" (CC, 1445).
The sacrament consists of four parts: a person who has sinned and is contrite (contrition) goes to the priest and confesses (confession) his sin; the priest absolves (absolution) him and then lays upon him a temporal punishment for which he must make satisfaction. Why confession? (1) The incarnational principle. (2) According to Kreeft, "throughout Scripture God's forgiveness is always mediated" (343).
The observance of this sacrament during the late medieval period was less than ideal. Steven Ozment provides this description:
"When religiously earnest people sought forgiveness for immoral behavior, they encountered a very demanding penitential system, one that provided only temporary relief, and even that with conditions attached and the threat of purgatorial suffering for unrepented sins. Full, unconditional forgiveness of sin and assurance of salvation were utterly foreign concepts to medieval theology and religious practice. Effective removal of religious guilt and anxiety this side of eternity would have meant the end of medieval religious institutions, and advocates of this-worldly perfection were roundly condemned during the Middle Ages" (216).
As Thomas Tentler explains, "one knows he is forgiven because he is willing to perform the overwhelming penitential exercises demanded by the church. The consolation of this system lies in its difficulty" (Sin and Confession on the Eve of the Reformation [Princeton Univ. Press, 1977], 14). Whereas confession and absolution in medieval Catholicism secured forgiveness from the eternal guilt (culpa) of sin, there was still the temporal guilt that called for punishment (poena) and suffering in purgatory. Tentler explains:
"According to the medieval theology of penance, a sinner must not only be absolved from his guilt but must also pay for his sins in the form of some kind of punishment. Purgatory is the middle place of destination for people who die absolved of guilt but with an outstanding debt of temporal punishment. Not until the expiatory fires of purgatory have 'satisfied' this debt will they enter heaven .
Obviously absolution from guilt is far more important than remission of punishment. Nevertheless, indulgences, which are ways of reducing the punishment owed for sin, aroused controversy in the sixteenth century because Christians retained a lively interest in that intermediate suffering place and wanted to avoid its worst or, if possible, all of its pains. And that is one reason why penance "the work of 'satisfaction' for sin that the priest assigns the penitent in confession is vital to the practice of forgiveness" (318).
Ozment agrees, explaining that
"in the final stage of the traditional sacrament, priestly absolution transformed this eternal penalty, justly imposed by God on the sinner, into a manageable temporal penalty, that is, something the penitent could do already in this life to lessen his future punishment; for example, special prayers, fasts, almsgiving, retreats, and pilgrimages. If such works of satisfaction were neglected, the penitent could expect to burn for his laxness after death in purgatory" (216-17).
Although the granting of indulgences was quite old in the RCC, it was refined by the papal bull Unigenitus of 1343 which set forth the treasury of merits. Thompson explains: "It was proposed in that bull that the Catholic Church holds as a treasure the infinitely copious merits of Christ and of all the saints merits far in excess of any that they themselves may have needed - and that the church may dispense these merits in the inexhaustible treasury to remit poena, that is, the recompense owed by living Christians" (Humanists and Reformers: A History of the Renaissance and Reformation, 395).