I don't think you could have picked a tougher book to try out a blurb. There's grammar stuff wrong in there I'm sure you're aware of. I think "this sweeping story encapsulates mans struggle in a faithless world..." should be nearer to the beginning. The word 'struggle' promises a juicy conflict. The only real problem I had is the last line. I think I know how it was intended to come across - tempting me to read it. But at first it seems insulting. Perhaps this is due to my own bias because these specific books produce emotion in believers and non-believers. I don't know how to better explain it than with an off-the-wall example. You're with your lover or significant other and they say "If I'm not good enough for you, no one else will be." Something about the wordage makes me feel insulted.
Am I making sense?