How can any one be sure about it until you actually reincarnate? Even then, you may not have any memories from the previous births. So this is some thing like god whose existence you cannot prove/disprove for certain as well.
Not related to this thread at all; but I have to say this. I think yours is the longest username in the whole of DP.
Sometimes what appears as real isn't and what is real isn't obvious to the natural eye. I said that to say this, "What appears as someone growing richer from greed isn't as it seems, maybe those persons are going through what they need to for spiritual growth." In the end there is no real gain when it's done for selfish reasons.
There are some theories revolving around a collective consciousness. But for me, yes I do believe in reincarnation and I have the scars to prove it .
I will be sure to start one. I personally have a very detailed "theory" of reincarnation. One of which is that "souls" (an imperfect term for an imperfect idea) can and do split, so that the spirit of one great person can become the spirits of many. The reason we would not "remember" this all the time in our daily life is because the ego is a construct of the spirit and not the spirit itself. Therefor behaviors, attitudes and prejudices would be cast away as the spirit "moved on". Part of the reason I like my theory of reincarnation is because it pretty much makes any new age attempt at using past life regression as a form of therapy useless since your current ego has nothing to do with your past life one except for a spirit-ual connection. I call it a theory because I do think there is evidence for reincarnation in the studies that have been done with past life regressions in hypnotherapy. I myself have been on a number of regressions preformed by a local licensed hypnotherapist and personally the only use I got out of it was an introduction to hypnosis and a useful parable played in 3d in my head.
But how can you be sure that, if reincarnated, you would be reborn in a favourable existence? Or at least one no less favourable than you’re in now. What is a favourable existence? Is being a human a favourable existence? Or maybe an animal? Or something else? In Buddhism reincarnation, or rebirth, is seen as an endless cycle one must break free from. Even people who do good things and are reborn in a heavenly realm will ultimately die (because everything changes and nothing lives forever) and have to be reborn and therefore experience unsatisfactory existences. The ultimate goal for a Buddhist is to attain nibbhana (nirvana) and live in a way that generates no karma (good or bad) and live out the result of previously generated karma with calmness or ‘equanimity’. The end goal being no rebirth and an escape from the never-ending cycle of samsara. Suicide simply shortens the cycle. This will all probably seem quite strange to those coming from the background of mono-theistic religions.