There are a lot of different types of books in the library - histories (often skewed by the writer), biographies, mythology, folk tales, poetry, spiritual/religious works, collections of correspondence, self help books...by a lot of different authors, with a lot of different perspectives. I get more out of some books than others, agree with some authors more than others. Some authors I can agree with some things they write, and other things they write are way off base (Paul is an excellent example).
The Bible isn't one book, or even one type of book. It's a library, a collection of writings, written over thousands of years by multiple authors - mostly, in some way, about God and God's relationship to us. Do I pick and choose what scripture "rings true" for me, what I believe is inspired writing? Sure do. =) Do I sometimes find wisdom or spiritual truth in a passage that is allegorical or historically inaccurate? Sure do. =)
And yes, you are absolutely correct, all history is hearsay. Even history recorded by eyewitnesses is based on the perspective, knowledge, and limitations of the observer.