Science is a methodology. It is not a belief, a cult following or even an ideology.
Science is simply the understanding of the natural world/universe/etc through a strict 5-step process:
So, what is a theory? A theory is a set of observations that are consistent, or a concept based on growing evidence or a large amount of supporting evidence/repeated results from observations and experimentation.
A theory CANNOT exist without being constantly re-tested. A true scientist will tell you that nobody, ever can be 100% sure of something, but you can be 99.9% sure! There is NEVER a way to test all possible hypotheses for a given subject!
Sometimes, 'bunk' theories can be thrown out because they are invalid. To quote a professor I had, "You cannot use the hypothesis that colds are caused by an imbalance of psychic energy."... There is no way to test this! No way to observe or record data for it, never mind that we already