'Fiction' and 'Non-Fiction' are nothing more than bookstore classifications to facilitate shopping. They are not a guarantee of the purity of a books' contents.

On religion, I'll take the bait: I don't think you can compare non-fiction books like a cookbook or an auto repair manual with a bible.

Organized religion represents a human attempt to explain and codify an innate spiritual feeling and/or yearning most humans across all cultures possess.

Human institutions like religion, politics, and education are fraught with frailty, and some of these (maybe all) have been corrupted from time to time by power and money.