I don't disagree that religions would exist. I just found BSG's religion very difficult to believe, particularly given the amount of influence it had over them. I mean, imagine that modern day people were fleeing North America via aircraft carrier. They know they're being chased by superior opponents and that they have to find some sort of remote land to settle in. Halfway through the journey, their Secretary of Education declares that some of the islands they were passing seemed very similar to those that had once surrounded the lost island of Atlantis. She thinks they should detour to one of the islands in order to search for the Gates of Sparta, which could point the way to the Tomb of Plato, which might contain a Golden Sextant that would show where Atlantis has been hiding all this time! And of course, everyone thinks this is a wonderful idea and that they should mutiny in order to check it out.
...REALLY?
And that's not the worst part, either. The worst part is that, of course, they were right to do so. Their crazy, stupid, no-one-in-their-right-mind plan worked out great, because darn if they didn't find the Gates of Sparta, Tomb of Plato and Golden Sextant on that random island. The whole thing just struck me as ridiculously stupid on the colonists' part, and even more stupid of the show's writers to make that a legitimate part of their journey.
Yeah, I don't find the political bickering unrealistic (as I did with the religion), I just object to the refocusing of the show around those issues. The show completely switched gears in the second season.