Karl Popper (think it was him anyway) said that something can't be true unless it can be proved false-- for example, if trying to prove the theory "All swans are white" you shouldn't look for all the white swans you can, only for black swans and if it is impossible to find a black swan then all swans must be right, proving the theory (or something along those lines) Therefore to prove the Big Bang theory correct, all other theories must be proved incorrect, as this would be pretty much impossible due to the fact that various dietys in various religions who supposedly created everything cannot be found as they usually occupy a celestial body only accessible by death Therefore the Big Bang theory will remain as such. In answer to the original question, religion is not reffered to in this way because everyone who believes it, believes it to be fact and there can be no other way it happened, many people who believe in the Big Bang theory would be likely to adopt a different theory if science proved it more likely. Religion has little to do with logic whereas science does.