If an individual lives a life of getting away with murder, rape, pillaging, and really anything against a simple human moral code and never gets caught, do you feel that the person just simply got away with it? I'm sure the answer is yes, but I'm curious as to where the barrier of living out our darkest desires and why we would bother with morality if we knew there was some way to simply not get caught for the things we do?
I have a few separate points to make about this. The first is that justice is important to people, which is why we establish laws for people to follow, penalties if they don't, and a system that is impartial as possible to keep people following those laws. So your question about what would happen if nobody got caught for doing harmful things doesn't apply in modern society. It's not a perfect system, but it tends to work pretty well keeping me safe most of the time.
Second, you'd be wrong to assume that fear of punishment is the only thing that keeps people from committing crimes. One thing is empathy for other people. Should I go on a killing spree? Why would I want to? I care about other people, and I would feel bad if they died because of me. It wouldn't be particularly pleasurable for me, I wouldn't get any benefit from it, and there's that pesky human justice system that would make the rest of my life unpleasant.
Third, maybe there is some doctrine out there that promises justice that distinguishes between people's good and bad actions... but Christianity is not that doctrine. I don't know what sect you follow, but many of the ones I'm aware of claim that we are saved through faith and not through good works. Most Protestants assert that we are all terrible sinners regardless of what particular things we've done, and every single person deserves eternal torture equally. A preacher like Ray Comfort doesn't draw a distinction between a guy like me, who just doesn't believe in God, and someone who (as you say) gets away with murder, rape, and pillaging. In fact, according to some preachers, this hypothetical murderer could experience a sincere conversion moments before he died, and he'd go to heaven.
So in promoting Christianity, I think you're really asking whether I feel bad that I won't ever experience eternal suffering as the just punishment for my own crime of not believing in your God. And the answer is no.