The Catholic. I'm still not entirely sure how 'sin' or moral actions and their consequences play a roll in Catholicism. For instance, do you need direct forgiveness from God for your actions? Do you compensate for your sins with good deeds like charity? It's almost like, to Protestants, you are only free to do evil. Meanwhile, both good and bad deeds are incorporated into the notion of free will for Catholics. It also seems as if Catholics use a mixture of scripture, tradition, and reason to derive their concept of sin, while Protestants are more affirmative about the Bible and it's view on sin, particularly the NT, which was exceptional because Jesus was teaching forgiveness in a time of ridicule and rigid traditional roles. He ate with all the wrong people. Talked with prostitutes washed people's feet, etc. I know it doesn't sound like much but at the time it was a major reformation.
The fact that some Protestants really only consider the Bible as the only canonical text gives them appearance of disregarding the events that took place after the 1st Century, the formation of the Catholic/Orthodox Churches in Rome, etc. Also gives them the appearance of not knowing... well, much else, not unlike myself.
The RCC church created most of the conceptions of sin and protestant conceptions of sin and salvation are pretty much reactions in one shape or another.
The original Christian conception of sin was so severe that it led scriptural scholars to consider the old testament a work of optimism and the new testament a work of pessimism, a fallen condition, a wicked evil world, a redeemer killed and everyone can look forward to uncertain judgement from a wrathful God.
That's until the Irish come into it, they created an optimistic turn with ideas about sin, the codification of sins into mortal, venial, deadly and a whole system of redeeming yourself through prayer, acts, confession and of course the dispised system of seemingly "buying" salvation through tithing the church and having masses said for you.
This is pretty much the point at which the Irish abbeys on the coastline pulled the world out of Dark Ages but its also the point at which a lot of protestants believe the whole thing went awry and their efforts at reform where apparently to return the church to an earlier stage, in his conflict with Erasmus Luther saw himself as a dogmatist trying to return the Church to orthodoxy.
An incredible, frankly amazing, irony considering that most, if not all, protestants I've encountered tend to believe that the reformation was a revolutionary modernisation and harbringer in a positive sense of civil and religious liberty, toleration, industrialism, capitalism, political revolution, democracy and modernism (I kid you not and its been backed up with BBC historical documentaries and books on the protestant revolution, which are very anglo-American).
At that juncture the RCC church held that a combination of faith and works would save you from eternal damnation, Luther bawlked at this suggesting that what could you do for God since he as the creater can have nothing from you which he didnt create or will in the first place. Personally I hold with Jung's idea, which owes something to German RC beliefs, that we each have a "spark" of God in us, so as it says in the scripture whatever we do to each other we do do God themself.
Luther's position was that you can be saved from sin not by confession, acts or anything else for that matter but by a leap of faith alone, you have to hope and pray. I see that as contra much of the Gospel of Mathew, which mentions the final judgement as says something very different, God not singling out believers from non-believers but persons on the basis of works, and the book of James, in which James suggest faith without good works is dead.
HOWEVER, RCC theologians have issued a consensus document with the Lutherans suggesting that the RCC church is no entirely reconciled to the Lutheran positions on this matter. Infact, so much so that no successive Pope, while they have questioned Vatican 2, has this consensus document and have even suggested, through the priesthood and at least the Jesuits, that individual RCs who dissent on this are committing sins.
Calvin's position was different, he believed there was an elect, this is grounded in old testament teaching about a choosen people, the mention again of a choosen people in the new testament and some of Augustines apart consideration of who was choosen too. The idea is that before you are born you are either justified or not, saved or not, its all already decided, your name is in the "book of life" or its not. If you are part of the elect it could become evident if you are rewarded with riches, which is ironic because not only did Jesus attack those doctrines when they where Jewish ones but also if you live a puritan lifestyle you'll accumulate wealth, if you live the protestant ethic you'll become rich because it coincides with capitalism.
There is a scots author Hogg who satirises this perspective in a novel called confessions of a justified sinner, its meant to be about religious fundamentalism in general though, in which a character believes he is saved, there is nothing he can do to reverse this, therefore he murders and commits crimes.
Now, years ago, life three generations the RCC church in Ireland had a position similar to one which the comic artist Crumb lampooned, that you where born sinful, if you wherent baptised you went to limbo, if you where baptised you where sinless but would commit sins naturally so it was important to have the sacrament of confession as often as possible from as early as possible. It preceeds communion and some older parishioners wouldnt and still dont receive communion without having had confession first. In addition to this, there where a number of baptisms, the baptism of fire (if you are martyred but not baptised by a priest), of water (the regular sort) and another which was to do with works and I believe governed those born and dying without hearing the gospel but living in accordance with natural law (this was used in later years by some people who'd argue that Ghandi et al couldnt possibly be in hell).
