“An indulgence is a remission before God of the temporal punishment due to sins whose guilt has already been forgiven, which the faithful Christian who is duly disposed gains under certain prescribed conditions through the action of the Church which, as the minister of redemption, dispenses and applies with authority the treasury of the satisfactions of Christ and the Saints.‘An indulgence is partial or plenary according as it removes either part or all of the temporal punishment due to sin.’ The faithful can gain indulgences for themselves or apply them to the dead.”(Catechism of the Catholic Church 1471)Allow me to explain.... Sin has a two fold affect: 1) eternal punishment, and 2) temporal punishment. Eternal punishment: hell. Temporal punishment: it’s temporal, it’s temporary, it’s something that will pass. So where do you get this ‘temporary punishment’ eliminated, or wiped away? Purgatory! You cannot enter into heaven with any guilt or stain on your soul, so a soul first spends time in purgatory to be cleansed. You’re still guaranteed heaven, but you’re polishing up your soul. We the faithful on earth can help in that 'polishing' and indulgences is one way to do this. By attempting an indulgence, we are doing something for a soul in purgatory, so that part (or all) of his temporal punishment will be washed away (and remember, an indulgence doesn't forgive a sin, its concern is with the punishment for a sin that has already been forgiven!).The idea of indulgences was once explained to me in the following way: if I break my neighbour’s window, I can be forgiven for the action… but that doesn’t replace the window. Someone has to go out and buy a new one. Now I can either spend the money myself to replace the window, or someone can help me pay for it.When I pray for souls in purgatory, when I try and gain indulgences for them, I am helping to pay their debt to God. It’s like I’m chipping in to help pay for that window!Now I said try and gain indulgences. I chose those words, because indulgences can be a little tricky. As cited above there are partial and plenary indulgences. Partial indulgences erase some of the temporal punishment, while a plenary indulgence wipes out the entire debt of temporal punishment.Partial indulgences are quite plentiful – saying a small prayer, making the sign of the cross, visiting a cemetary, etc.; these can all be partial indulgences! (see The Enchiridion Of Indulgences for an outline of actual indulgences.) The one requirement is that you must be in a state of grace (that is, not in a state of mortal sin) and be sorry for other venial sins. Plenary indulgences are significantly more difficult to attain, and unlike a partial indulgence only one may be gained per day. Obviously to receive the plenary indulgence one must be in a state of grace and actually perform the prescribed act, but one must actually have the intention of gaining the indulgence, receive Communion and a sacramental Confession within eights days of performing the act, say prayers for the Holy Father’s intentions, and be completely free from any attachment to venial sin (these are the 'usual conditions' referred to in the Catechism). It’s not an easy task, but certainly a task that is worth attempting!Indulgences have been misunderstood over the ages and have not only been a great source of criticism from those outside of the Church but you have also been a source of abuse within the Church. This does not, however, mean that we should disregard them. They help to remind us that we are all connected together in the body of Christ. And because of this, our charity may not only help souls in this life... but also benefit those souls who are cleansing themselves in purgatory awaiting heaven.