It's religion for one simple reason. Despite the general assumption that "theory" just means an idea someone came up with or a plausible idea, in scientific terminology that is a hypothesis. A theory is a hypothesis that has been proven by observation and experimental data. So, due to the complete lack of experimental data for creationism it is a hypothesis, therefore no proof, therefore faith is required in its existence, therefore it is religion. The Big Bang theory, however, as well as the theory of evolution, the theory of star and planet formation from nebulae collapse and whilst we're at it the theory of global warming have all earned the title of theory through thorough and strict examination of evidence. Be it by observation of galaxies and nebulae several thousand to several billion light years away allowing us to see several billion years in the past, examination and comparison of fossils of various ages, gaining temperature records of the past several million years from ice core samples of whatever. Otherwise it would be called the hypothesis of evolution. That's why I always laugh when creationists say "it's called a theory for a reason". In my head I'm saying "yeah, because there's bucket loads of evidence proving it. Killed your own argument there..." Lol. [spoiler]Nothing beats the inquisitive mind[/spoiler]