"Proof" of an after life, it could be argued, is a matter of one's own perspective. While 90% of the world (it seems, at times) take such things on faith alone, there's likewise a huge percentage that believe that one must earn that "next life". While that sounds like reincarnation thinking it's not completely; moving into a new existence or state of being, including such things as Heaven (or hell) are akin to the famed caterpillar metamorphosis; on one level we have ceased existing and yet, we return in a newer "higher" form.
The big issue is what survives after physical death.
I've been reading a book by J. Allan Danelek entitled "
The Case for Ghosts -- An Objective Look at the Paranormal" (I strongly recommend it for the skeptic & believer alike in that it comes so close to offering that "balanced" sense of things you hear me preach about so often
). The author presents some wonderful suppositions with the earlier chapters delving into this very question; what is it that survives death if anything? What is the "soul"?
Danelek brings out several points of consideration that few seem to contemplate. Of course, I don't believe everything he suggests but at the same time, I feel he's closer to being on the "right" track with his views than not (and so I'm looking forward to reading his books on Reincarnation, etc.)
There have been some interesting articles over the past few years in Psychology Today, UTNE Reader, and TIME in which this issue is being discussed from a variety of perspectives; frequently sitting the orthodox/religious ideologies to the side and dissecting the idea of life after death from the more analytic point of view.
I'm very much a reincarnationist in that it, alongside the law of Karma, seem the only logical course in things if some part of our "ego" survives physical death. I'm simply not able to accept the idea that we are born to ultimately become worm food and fertilizer. Granted, that is very much the reality behind our physical shell, but I can't believe such to be "the ultimate goal", so to speak.