Scientists start with the assumption that there is no purpose to life and that material things can 'just exist'. Therein starts the purely material philosophy of science.
Other people start by thinking that nothing can exist without a purpose and therefore they try to find a meaning and purpose to life in the world.
Both are valid assumptions to begin with.....but what do we observe?
We observe that life has taken a very complex and sophisticated path leading to humans. In addition to that, we have eminent physicists supporting the idea of Consciousness being fundamental in the universe. We also have phenomena like NDE's and reincarnation events (in the OP). What does all this show? It clearly supports the second assumption of there being something more than chance driven material existence.
This should be clear enough for everyone...but no...not for science enthusiasts!
So...what do they do? They dig in their heels and start arguing that there need not be any answer to the 'Why' question. NDE's are hallucinations. Reincarnation incidents are rubbish and made up. Things can 'just exist'. Evolution of complexity is entirely due to random variations and chance environmental factors....and so on and so forth!
Sriram,
Science doesn't dig in its heels, as you are wont to suggest. On the contrary it will go where the evidence leads, and, so far, it finds the evidence for things like NDEs(see Sam Parnia's Aware Project) and reincarnation claims as little more than anecdotal. For you, they seem to suggest some sort of meaning and purpose to life(whatever that is), but science is much more exacting than your personal feelings and experiences.
You also seem to completely misunderstand evolutionary theory which does not have homo sapiens as an end result, as you seem to think. You even make the silly assumption that those who disagree must rely on pure chance driving material existence, totally ignoring the entirely rational idea that survival has at least as much significance.
I also note that whilst you are very quick to ask why cells or molecules need(?) to exist, and immediately seem to deride others for suggesting that 'why' is a rather meaningless question, you seem very loathe to answer the alternative question I put to you, which was, why shouldn't they exist?
You seem to start with your ideas about consciousness, spirituality and overall purpose(except you can't seem to answer 'Why'), and then concentrate on dubious so called evidence to back up your ideas, whilst ignoring any ideas and evidence which conflicts with your particular scenario. That's your prerogative, of course, but don't expect me to follow. I'll go where the evidence leads, and have a complete willingness to change my views. So far, I see nothing in your meanderings(and, much more importantly in the scientific world) which would tempt me to do this.
I would politely suggest that rather than 'science enthusiasts' who dig in their heels, it seems to be you who are guilty of that particular characteristic.