Same thing with foundation vs. evidence. If you don't think a book can be foundational, how about a few pieces of paper? The U.S. Declaration of Independence and Constitution are considered our foundational documents. Yes, the first especially lists verifiable grievances against King George, but most of it represents values in which many Americans still have faith/in which they still believe.
Personally, I interchange belief and faith in some cases. If a friend is worrying over passing a professional exam, I might tell her she'll do fine, just "have faith in yourself", or equivalently "believe in yourself". On a more theoretical level, I would use faith to mean an individual's or group's body of beliefs, with "belief" defined here as those things we accept in the absence of proof. Sometimes we have evidence, but it may be far from convincing. It is almost impossible to go through life without beliefs, even if we understand they may be incorrect and are subject to revision. In one sense, they can be viewed as working hypotheses. It is not wrong to put great stock in them, as long as you are willing to revise them should (more) evidence appear. Until then, though, they are just as valid as anyone's, and are best measured on the results they produce.