What are the pros and cons of creationism being taught in science lessons?

I go to a Catholic school and they don't teach Creationism in Science lessons. I can see from a Theist point of view that science is theory as well as fact and if you believe that Creationism is either one of them then maybe its plausible in a Science lesson. But me personally, I believe that Creationism should be left out of the Science room cause its not a proven fact, its Faith. That's why we have separate R.E cles for that where people can express this. Hope this helped =]