I have read many books and never have I asked in my summing up of a book, "Is this book true?"
How can I possibly know that? If I did ask and did a hell of a lot of research, I probably would never find out the whole truth, because I did not write it. I would have to take the author's word for the meaning and there lies no proof. There is no writing that does not contain a part of the author.
I form an opinion of books relating to how I am affected. I ask questions of myself. Is there information I relate to? Is it well written? What does the author mean? What led the author to that meaning? I may agree with the author or I may not. The book will mean precisely what I think it means, to me. It may mean something completely different to someone else and that is o.k too.
Why do you use a completely different criteria when reading the book called the bible?