All Souls Day: The Faithful Departed
All Souls’ Day commemorates the faithful departed. The Roman Catholic celebration is based on the doctrine that the souls of the faithful which at death have not been cleansed from the temporal punishment due to venial sins, or have not fully been purged from attachment to mortal sins, cannot attain the beatific vision in heaven yet, and that they may be helped to do so by prayer and by the sacrifice of the Mass.
In other words, when they died, they had not yet attained full sanctification and moral perfection, a requirement for entrance into Heaven. This sanctification is carried out posthumously in Purgatory.
One of the most commonly recited Catholic prayers, Requiem Aeternam (Eternal Rest) has fallen into disuse in the last few decades. Prayer for the dead, however, is one of the greatest acts of charity we can perform, to help poor suffering souls during their time in Purgatory, so that they can enter more quickly into the fullness of heaven.
Eternal rest grant unto them, O Lord, and let perpetual light shine upon them. May the souls of the faithful departed, through the mercy of God, rest in peace. Amen.
Requiem aeternam dona eis Domine, et lux perpetua luceat eis. Requiescant in pace. Amen.