When we commit sin, we have guilt and punishment before God. Through the Sacrament of Penance the guilt is forgiven, but the punishment remains on our soul and must be satisfied. This is what we call temporal punishment. This punishment is purified through practices of penance, good works in this life, indulgences or after death in Purgatory. If it removes all of the temporal punishment due to sin it is called a plenary indulgence, whereas if it removes only part of the temporal punishment due to sin it is called a partial indulgence. Indulgences are linked to the forgiveness of sins.
An indulgence is a grace or favor granted by the Church accompanied by a pious action—a prayer or visit to a shrine—which remits the temporal punishment due to our sins already forgiven (cf. Catechism of the Catholic Church, 1471-1473).
We can use an example to help us: imagine that you hammer a huge nail into a beautiful wooden picture, causing a lot of damage. Confession, which forgives our guilt, is like taking the nail out of the carving. But the hole remains and must be repaired, which would be the temporal punishment and consequences of sin that must be purified either in this life or in the next. Indulgences are for this purpose. They are favors that the Church grants, through Christ’s merits, to help us purify ourselves of the punishment we must satisfy for because of our sins.
God is the one who forgives sins, but He does so through the Church and her ministers by the authority Jesus Christ conferred to the Apostles and their successors: “If you forgive the sins of any, they are forgiven” (John 20:23). The conditions established by the Church to obtain an indulgence are: 1) Perform the indulgenced work in the state of grace; 2) the general intention to gain the indulgence; 3) go to Confession, receive Communion and pray for the Pope 20 days before or after the indulgenced work; 4) have a disposition which totally excludes all attachment to sin. Under these conditions you can gain a plenary indulgence every day and apply it to yourself or a deceased person.
For example, you can gain a plenary indulgence by going to Eucharistic Adoration for ½ hour, praying the Rosary in a group, reading Sacred Scripture for ½ hour, etc.
So, it is good to talk about indulgences nowadays because it is a manifestation of God’s infinite mercy which, through the Church, “desires all men to be saved” (1 Timothy 2:4). Christ not only forgives our sins; He applies the curing balsam of his infinite merits on our wounds.
-Response from Fr. José Luis Saavedra, SHM