Again I think you're confusing the word with it's common usage, here's the last sentence of the introduction.
Or from the American Association for the Advancement of Science:
I'm pretty sure you've got a scientific background JJ so I think you can appreciate the fact that a theory attempts to cover a pretty broad spectrum regarding a certain phenomena. It's never going to be a law because of that, but it can reliably predict an outcome for a subject. All I'm saying, and I think you agree here, is that we really shouldn't be comparing "faith" in science to "faith" in religion. I don't even want to use that words in a scientific sense, It's like saying you don't trust what you are seeing/calculating.