Disposable Hero:
I think for SOME people, those individuals who NEED authority to tell them what's right and wrong, it keeps them in line, which is probably a good fruit. I'll qualify this by saying that I don't need to be told that sleeping around would hurt my wife, so I don't do it, (having a face like a bag of spanners has nothing to do with it!) However there are some that need to be told, for them I think religion is probably a good thing.
Perhaps you are right - I am no psychologist. I think though that being "told" does not give people moral direction if their moral compass is faulty to begin with. Being told what they did was morally or spiritually wrong may cause them to "regret" their actions but I highly doubt it's very effective at keeping them in line. Certainly secular laws seem to have little or no effect on those who have a propensity for poor behavior, in fact it rarely even corrects that behavior. What makes you think religious threats or guidance would have a better effect?