In Norm 1 of the APOSTOLIC CONSTITUTION OF POPE PAUL VI, INDULGENTIARUM DOCTRINA, it states:

"n. 1—An indulgence is the remission before God of the temporal punishment due sins already forgiven as far as their guilt is concerned, which the follower of Christ with the proper dispositions and under certain determined conditions acquires through the intervention of the Church which, as minister of the Redemption, authoritatively dispenses and applies the treasury of the satisfaction won by Christ and the saints."

Jimmy Akins' article starts this way:

"You've heard it many times: "Catholics used to believe in indulgences, but we do not believe in them today." This statement is heard from the lips of many Catholics, even from some priests. It is said with mild embarrassment and a desire to close a chapter of Church history with which many Catholics feel uncomfortable.

Those who claim that indulgences are no longer part of Church teaching have the admirable desire to distance themselves from abuses that occurred around the time of the Protestant Reformation. They also want to remove stumbling blocks that prevent non-Catholics from taking a positive view of the Church. As admirable as these motives are, the claim that indulgences are not part of Church teaching today is false.

This proved by The Catechism of the Catholic Church, which states, "An indulgence is obtained through the Church who, by virtue of the power of binding and loosing granted her by Christ Jesus, intervenes in favor of individual Christians and opens for them the treasury of the merits of Christ and the saints to obtain from the Father of mercies the remission of the temporal punishment due for their sins." The Church does this not just to aid Christians, "but also to spur them to works of devotion, penance, and charity" (CCC 1478).

Indulgences are part of the Church's infallible teaching. This means that no Catholic is at liberty to ignore or disbelieve in them. The Council of Trent stated that it "condemns with anathema those who say that indulgences are useless or that the Church does not have the power to grant them."[1] Trent's anathema places indulgences in the realm of infallibly defined teaching.

This was not the first time an ecumenical council had discussed indulgences-the first times was in 1415, when the Council of Constance affirmed the practice-but at Trent the doctrine was proclaimed infallibly for the first time.

The pious use of indulgences goes back centuries, far beyond the Council of Constance, into the early days of the Church. The principles underlying indulgences extend back into the Bible itself. Catholics who are uncomfortable with indulgences do not realize how biblical they are. The principles behind indulgences are as clear in Scripture as those behind more familiar doctrines, such as the Trinity."

Please read this important article.