Theory is wrong word
At this point, natural selection is an observable process. We can watch it happen. We have known cases. We can perform experiments that clearly demonstrate the mechanism. Its not a theory. Its a documented mechanism.
Creationism, OTOH, is a fairy tale with no evidence to back it up other than the book in which the fairy tale is written.
"The significant problems we face cannot be solved at the same level of thinking we were at when we created them." --Albert Einstein
"This is still a dangerous world. It's a world of madmen and uncertainty and potential mental losses." --George W. Bush