Even to better themselves is a payoff. For every yin there's a yang. Those that adhere to their religious beliefs just seem to take it that one step further (my mother-in-law is the REAL 'Church Lady') and truly believe that everyone gets their 'just reward' after death.
While I don't believe really in any deity at all and I think that, for the most part, we do just 'die', I also believe there's something...energy, souls, something...too many coincidences in life that can't be written off as coincidence, but won't hijack this for that.
I see more of the 'justification' for things as being used in believing the bible-that anything can be explained away as "God's will", be it hurricanes, war or alcoholism. Of course, if a believer doesn't like how things go, ie; homosexualism, it's also 'God' who could 'fix it'....just reminds me of a 3 year old who doesn't want to be punished for breaking something, "wasn't ME, Momma-GOD did it!"