"Reality", of course, is even more indefinable. But this is strangely not a problem, since reality is simply the what IS -- that which is the case. It doesn't have to be defined. Indeed, if it could be "defined", it wouldn't be reality.
Clearly, this subject is too big for a few paragraphs (or libraries), but (and this is critical) for most religious folk, there's no mystery or confusion here at all since their act of faith is that the priests and sheiks have God (= reality) by the throat. Whether the pontifications come from Rome, Baghdad, Tel Aviv, or your cult of choice, they always have that ring of fundamentalist certainty.
But we also know that many church goers are tongue in cheek about the "holy books" and the self proclaimed masters of those who know.
Naturally science comes into this as well, but science is usually pretty fast on its feet when it comes to making factual, but "non reality" statements. Certainly science addresses reality in SOME sense (e.g., if the Bush administration wasn't so ANTI science, the murder of New Orleans would never have happened and the ozone holes above the Earth would not be fatally widening), but science never pontificates. It never attempts to trap truth in a book or pulpit.
Historically, reality people, the seemingly trustworthy mystics (for the lack of a better word) have never been first scholars or even scientists. Rather, with such people, truth is always one on one. Interestingly, the root of all the world's religions goes back to such transcendental individual/reality moments, sometimes called Enlightenment or Awakening.
Our planet is now in mortal danger of being destroyed by religious fanatics. These are not reality people. They are usually illiterate humans in the grip of fear. They have time warped from the Dark Ages into the 3rd millennia and they have contaminated our constitutional government with their diaper religious beliefs.
Tragically, history has been far less influenced by people with moderate religious views (who tend to mind their own business), than by people who feel "chosen" and bury their cowardice and hate in "holy wars" and crusades.
Religious fanaticism is simply institutionalized psychosis and if we ever needed all the help we could get from reality folk (mystics) and courageous scientists, it's now.
Our planet simply cannot be pummeled any longer by these nut cases without passing infinitely tragic points of no return.
T.S. Elliot spoke of ending with a bang or a whimper. Let's not permit Mother Nature and our beloved (and one and only!) planet Earth to end with a Bush/Republican whimper.
