>While still billions of people believe in Allah, God or whatever without any evidence. I dont know how this can happen...
Isn't it obvious? In both cases people do the smart thing (which is not necessarily the "objectively correct" thing).
Faith in Allah, God etc, is a good social glue, and is personally comforting, helping regulate emotions, etc.
Similarly, not believing the Snowden story helps them fit with their social group (e.g. republicans), relaxes their mind from a whole lot of worries and concerns, helps re-enforce their personal beliefs (e.g. in good government), etc -- and most importantly, has no real disadvantage in their day to day life and work...