I wouldn't say it isn't science. It is a theory. Basically all science is is theory's, and stay theory's untill proven. The evolution is a theory, we don't have technology or knowledge to understand exactly HOW to universe started. Everything in the world today is matter, which is made of atoms, which is made of protons/neutrons/electrons, which is made of quarks[6 different ones] which they are thought to be made from little strings vibrating. Honestly I am christian, I do believe in creationalism as how the world started. I also think evolution is a good theory. Yet evolution could not happen unless SOMETHING created the first pieces of quarks/atoms/matter.
I believe in schools kids should be taught different THEORY's on how the universe was created. Children/teenagers should decide on there own, and I don't think either way should be "pushed" onto someone. Both theory's should be introduced. & creationalism is not just christian/catholic, basically ALL religions have some sort of god/gods that "created" the universe. So instead of saying "god created the earth in 7 days[which could have been hundreds of thousands of years...wont get into that]" say "one theory is that a higher being or spirit spawned the universe" or somthing along those lines.
Sorry this is long hahaha. I am obsessed with physics, time, and the universe so I tend to ramble. :]