(In response to the thread in the previous post.)
Most Jews don't know anything about gilgul - it's not a mainstream thing, except among Hassidim. I think its idea - that people get reincarnated in order to correct the past mistakes or finish some unfinished business - is somewhat in contradiction with the rest of Jewish eschatology, where people get ressurected as a reward for having been reasonably good in their past life, not as a punishment for having been bad.
But that's OK. Jewish eschatology is more of a mess than the EU constitution, and much for the same reasons.
I get your point about religion (one's own or someone else's) being useful to some of the users. I certainly don't have anything against the fact that you use it to avoid harming yourself.
The reasoning behind the belief in reincarnation is incomprehensible to me for the same reasons that Adelphi mentioned: if the personality disintegrates, who is there to be punished or rewarded, and if the only thing that remains if some "essense of self" that does not contain any personality or memories, how is this different from a regular death?
As for my personal beliefs:
Emotionally the whole thing is even more incomprehensible to me. From my point of view, life is definitely not full of suffering, and whatever suffering there is in life is usually derived from death (and in general life's finiteness) one way or another, and not from craving. The world is not a bad place, and people are not in general evil. I'd very much like to live forever, especially if I get to remain reasonable young and healthy, and I wish most other people lived forever, except if they really don't want to.
From this point of view, reincarnation as a punishment is a strange idea indeed.
I used to know a Buddhist some years ago. He explained to be that being attached to anything on this earth is bad, because you can always lose it or live in fear of losing it, and this would cause suffering. To me the idea makes about as much sense as "absolute zero is the best temperature, because it least it can never get colder".