I'm reading Peter F. Hamilton's Night's Dawn series at the moment. He weaves a fantastic tale of humanity's chance encounter with energistic forces beyond our understanding which force us to confront the reality of an existence after death. But it's a reality which has a scientific basis; it is only our lack of understanding which makes it seem otherwise.
I'm not sure that we'll ever find the truth, but I do believe that
if there is an afterlife, we'll one day come to some satisfactory, scientifically verifiable conclusions. But if there is
no afterlife, how do you demonstrate that nothing exists? And you can't use logic to prove or disprove that an afterlife exists if that logic is based on unsound assumptions.
I agree with what Michael said about the essences of religion, and I think religion is that way because of our initial lack of understanding, coupled with a need for certainty, and a willingness to believe and follow authority figures.
We're born into this world with only our instincts. As we gain a little comprehension of our existance, and some measure of self-awareness, we also become aware of all the gaps in our understanding. We're confused by and perhaps fearful of things that don't make sense to us, so we try to explain them in a way that lays that fear and confusion to rest. And when we meet someone who states their beliefs emphatically, as fact, not opinion, in our more malleable states of mind (which for some people is their
only state of mind) we accept their words and make their beliefs our own, also labelling them 'fact'.
As nara pointed out, we can also label our own experiences in a way that assigns them spiritual meaning, and if we're convinced enough of the explanation we tell ourselves, then it's quite likely we could convince others. And a leader who has such experiences could convince a lot of people.
Of course it's possible for those experiences to be real, and those explanations to be valid, and thus we're willing to believe them, and tell them to others, and even have similar experiences ourselves. But sometimes those experiences are not the same as the ones mentioned in the stories we hear.
As an example, I've had many experiences of
sleep paralysis. What I experienced was another presence in the room, sometimes clearly defined, mostly not. The first such experience almost convinced me my house was haunted; it was that 'real'. Subsequent experiences allowed me to form an understanding of the environment which gave rise to the experiences, and I'm now certain I could recreate the experience any morning (but you'd have to give me a damn good reason to put myself through that again!)
But the point is, I could have told myself it was either alien abduction or ghosts, but since my influences are scientific, a chemical imbalance seems more likely to me,
even though the exact physiology is still unknown. So the scientific and physical world is influenced by the stories we tell just as much as the spiritual and metaphysical.
But as Andy said, new stories could launch us into a new level of inquiry, and who knows, those stories may be the same in both the spiritual and physical worldviews.