Do religious people repeatedly reject temptation in general? If not, would this not make religious people less trustworthy, since one cannot predict their future behaviour, and would make expecting moral behaviour from such people also another such bias.
Is striving towards a challenging ideal superior to ignoring that ideal or paying it lip service?
If you think it through the answer to your question coupled with the answer to mine provides a framework for understanding the outcome data presented upthread (the differing level of wellbeing reported by the very religious, the 'moderately' religious and the unaffiliated).