The argument over
faith and
works has supposedly been one of the cornerstones of the theological debate between
Protestants and
Catholics. In fact, there isn't any irreconcilable difference between mainstream Catholic and Protestant
theology on the topic.
Martin Luther developed the teaching of justification by faith alone in response to the excesses of emphasis on faith and prayer for others. During the Middle Ages, many people came to believe that they would be saved fromdamnation if they said the right words or carried around the right objects. These ideas were never officially endorsed by the Church hierarchy, but they weren't particularly discouraged either--partly because a lot of people were gaining money and prestige from their perceived ability to provide tickets to Heaven. Salvation increasingly came to be seen as something that could be purchased or negotiated.
Luther reacted against this by talking about salvation by faith alone, meaning that a personal decision to follow God was all that one needed to be saved--the amulets and special prayers weren't necessary if you had faith, and wouldn't help you if you didn't. Justification by faith alone because the theological epicenter of the Reformation, since it affirmed the individual's ability to be saved without mediation or intervention from an ecclesiastical hierarchy, and without going through any rituals that could be put under human control.
Despite the conflicts and mutual condemnations over the centuries, the mainstream Catholic and Protestant views on justification have never been irreconcilable--and as mainstream views have changed, they are relatively easy to reconcile today. The Catholic Church has always said that rituals have no benefit if they're not performed with real faith and contrition...and today, that idea is pretty much accepted by ordinary Catholics as common sense. Almost all Catholics would agree that if Stalin had a deathbed conversion, he would be saved even though he was unable to perform any good works. At the same time, there are very few Protestants who believe that works are really irrelevant. If you ask most Protestants what happens to a person who has a moment of true faith and then commits every sin in the book, most of them will agree that this person doesn't get into heaven--although most of them will say that it's because he didn't really have faith in the first place.
The point is that both Catholics and Protestants generally agree on the most important things--you don't have to do anything in particular to be saved, but "being saved" isn't something that excuses you from an obligation to do good.