In the words of the great poet (if abysmal human being) Philip Larkin, religion was invented solely to deal with the universal human fear of death.
Never mind all the theological blather which has as its central purpose the legitimation of the unprovable. Never mind all the murmuring rituals, the kneeling, the bowing towards Rome or Mecca or wherever, the wafting of incense, the rustle of the elaborate gowns of the priests, the fanatical self-flagellation, the total hypocrisy of doctrine and practice, the vast divide between the abject believers and the gold-shrouded clergy and never mind all the rest of the clap-trap which constitutes religious belief and practice. For the naked fact of the matter is that behind this elaborate and ridiculous facade lies a simple truth: religion, all religion, all religions since time began were invented solely to pretend that we don't die.
Think about it. Whether its Christianity with its central theme of resurrection, or the Muslim rewards of numerous virgins in the after-life, or the shamanistic prospect of total (and endless) unity with nature and on and on, all religions have as their central concern, their very raison d'être, some after life, some heaven and hell, some body-less NIrvana. That this fear has been parlayed into powerful organizations, very much of this world when it comes to accumulating riches and/or political power, is testimony to the profound centrality to human life which is the fear of death.
I believe that once we have faced this truth squarely we will be much less inclined to make ourselves party to the ridiculous, dangerous, illogical, unprovable, abject practice of what is called religion. Think about it again, if fear of death wasn't a profound and universal emotion, could anything as patently silly as religion be able to obtain such a purchase on us? Not likely.