A plenary indulgence is a grace granted by the Catholic Church through the merits of Jesus Christ, Mary and all the saints to remove the temporal punishment due to sin.
The indulgence applies to sins already forgiven. A plenary indulgence cleanses the soul as if the person had just been baptized.
A plenary indulgence can be obtained during Holy Week for oneself or for a deceased person if one of the following works established by the Church is performed.
1. If during the solemn reservation of the Blessed Sacrament (typically on a side altar), which follows the Mass of the Lord's Supper, you recite or sing the Eucharistic hymn “Tantum Ergo.”
2. If you adore the solemnly reserved Blessed Sacrament for a half hour.
1. If you venerate the Cross in the solemn celebration of the Lord's Passion.
2. If you piously participate in the Stations of the Cross
1. If two or more people pray the Holy Rosary.
2. If you attend the celebration of the Easter Vigil at night and renew your baptismal promises, which is part of the liturgy of that Mass.
Conditions in all cases:
In order to obtain the plenary indulgence, in addition to performing the specific works mentioned above, the following conditions must be fulfilled:
1. Detachment from all sin, even venial.
2. Sacramental confession, Holy Communion and prayer for the intentions of the pope. These three conditions can be fulfilled a few days before or after performing the works to gain the indulgence, but it is appropriate that Communion and the prayer take place on the same day that the work is completed.
A single sacramental confession is sufficient for several plenary indulgences, but frequent sacramental confession is encouraged in order to obtain the grace of deeper conversion and purity of heart.
For each plenary indulgence that is sought, however, a separate Holy Communion and a separate prayer for the intentions of the Holy Father are required.
The prayer for the intentions of the Holy Father is left up to the choice of the individual, but an Our Father and Hail May are suggested.