Often beliefs are unsupported by facts. The majority who claim to be believers have simply accepted someone else's ideas, interpretations, or simple musings.
If you make a decision to accept any of those human reasoning's as pure truth. Why even examine them at all? I mean if it is really THE TRUTH what more could anyone want?
If you stumble across or happen to notice that just one of those accepted 'truths' is not based on facts, then what does your own internal reasoning want to do? RE- examine your first impression.
It is the method by which all FACTS are substantiated, science goes about looking at every it's currents positions (beliefs) in this very normal sequence of re-examination. In the dark ages when religion and governments prevented the free exercise of this testing, examining, and discovery of facts, everything level of society suffered. Instead of making leaps and bounds of knowledge and understanding as was the case prior to those days, it was on a world wide scale 'dark' and foreboding full of myths, fears, devils, and superstitions.
When man finally came out from under so much fear and religious suppression, the world reflected a brighter day...no longer as dark.
As another poster so well said. Read, read, research, accept no man's ideas without enough facts to prove their position.