an alternative mechanism suggests itself. Individuals with a belief in supernatural assistance may be encouraged to perservere under conditions where a more realistic assessment of the situation would lead to just giving up. Those few who did survive against great adversity because of this belief, however few in number, would be preferentially selected for and pass this predilection off to their offspring. Those who didn't survive were going to die anyway, so the mistaken belief would prove no evolutionary disadvantage.

From a societal point of view, religion has one further advantage: that there is a reason why things are, and it is accessible to the human mind. That is, after all, the root concept behind science.