Hi Beno, I think you gave a beasutiful answer to there question. Here is a little of what Wikipedia Encyelopedia says ;
Main articles: Prayer for the dead and Indulgences;
Catacomb inscriptions include prayers for the dead.The Roman Catholic Church teaches that the fate of those in purgatory can be affected by the actions of the living.
In the same context there is mention of the practice of indulgences. An indulgence is a remission before God of the temporal punishment due to sins whose guilt has already been forgiven. Indulgences may be obtained for oneself, or on behalf of Christians who have died.
Prayers for the dead and indulgences have been envisioned as decreasing the “duration” of time the dead would spend in purgatory. Traditionally, most indulgences were measured in term of days, “quarantines” (i.e. 40-day periods as for Lent), or years, meaning that they were equivalent to that length of canonical penance on the part of a living Christian.When the imposition of such canonical penances of a determinate duration fell out of custom these expressions were sometimes popularly misinterpreted as reduction of that much time of a soul’s stay in purgatory. In Pope Paul VI’s revision of the rules concerning indulgences, these expressions were dropped, and replaced by the expression “partial indulgence”, indicating that the person who gained such an indulgence for a pious action is granted, “in addition to the remission of temporal punishment acquired by the action itself, an equal remission of punishment through the intervention of the Church”
Historically, the practice of granting indulgences, and the widespread associated abuses, which led to them being seen as increasingly bound up with money, with criticisms being directed against the “sale” of indulgences, were a source of controversy that was the immediate occasion of the Protestant Reformation in Germany and Switzerland.
Purgatory as a physical place
In antiquity and medieval times, heaven and hell were regarded as places existing within the physical universe: heaven “above”, in the sky; hell “below”, in or beneath the earth. Similarly, purgatory has at times been thought of as a physical location. In Dante’s fourteenth century work The Divine Comedy, purgatory is depicted as a mountain in the southern hemisphere. This is no longer the mainstream religious concept of purgatory. In 1999 Pope John Paul II declared that the term (‘purgatory’) did not indicate a place, but “a condition of existence”.
[edit] Roman Catholic statements
The Compendium of the Catechism of the Catholic Church, first published in 2005, is a summary in dialog form of the Catechism of the Catholic Church. It deals with purgatory in the following exchange:
What is purgatory?
Purgatory is the state of those who die in God’s friendship, assured of their eternal salvation, but who still have need of purification to enter into the happiness of heaven.
How can we help the souls being purified in purgatory?
Because of the communion of saints, the faithful who are still pilgrims on earth are able to help the souls in purgatory by offering prayers in suffrage for them, especially the Eucharistic sacrifice. They also help them by almsgiving, indulgences, and works of penance. Hope this helps! …Blessings,Robert