Look. If a proposition cannot be accepted as 100% true, then what do we call it when we accept the proposition as true anyway and act accordingly? What do you call the percentage, however great or small, that is subject to rejection, or doubt, or revision, or correction?
Apparently you are so used to equating "faith" with wild-assed guesses you do not realize that faith is, in most cases, based upon solid evidence. Faith and evidence are not exclusive of one another. They compliment one another. Reason, however, is entirely capable of misinterpreting and misapplying the evidence.