It is funny how the concept of sin (moral failure) is understood, at least in a general sense, by people everywhere. We usually see it very clearly in others (especially leaders) and denounce it roundly, and that's not necessarily a bad thing at all. However, it's a case of cognitive dissonance when we begin to suspect we may be tainted as well as those guys; how do we resolve that?
Until you finally get to that point, the gospel really looks irrelevent.
An aside... I can't remember the precise formula, but the Mormons don't believe that Jesus died for all sins. They believe he died only for Adam's sin and that took out the worst-case scenario for everyone. Then, whatever you do as a Mormon (rack up points thru temple stuff and other good behavior) or non-Mormon (be nice or not as nice) lands you in one of various places (in a harem, on a new earth, as a new god with a harem, for example). So, if a Mormon, I guess you should "do more".
Just a couple thoughts.
bebu
PS: BTW I'm a Christian, not a Mormon, and as such think he did die for my sins. I find it very relevent.