"Religion is a belief, science is a fact"
Science is based on some facts, but also theories that have not always proven to be factual. Example, the theory of evolution, and it's multitude of missing links.
You have very large misunderstandings about what science actually is and isn't. First, science does not deal in "proof". Second, there are far fewer "missing links" in evolutionary biology than most people try to imply. Third, The evidence for evolution is overwhelmingly huge and independently cross-confirming -- the few paltry things that naysayers can point to that are "missing" are entirely beside the point, and such complaints are intentional attempts to deceive and distract from the existing evidence.
Actually "facts" in science are far more susceptible to change than a theory. Also not matter how much evidence is accumulated, a scientific theory will never change into a "fact" or a "law".
Also there is more evidence and backing up the theory of evolution that gravitation theory.