Bibles write themselves. One story gets shared at a campfire amongst not very skeptical people (normally children and credulous adults ) and they adopt this story as true and give it sacred place in their culture ( sacred is another way of saying 'don't question or doubt' ) Another similar story gets shared and so on. Storytellers have different motivations, some are hoaxers seeking a bit of glory, some are political manipulators seeking power, some are social manipulators seeking to unify or objectify certain groups, some are subject to perception failures and poor memory and some are mentally ill. As long as the story resonates and produces an emotional response it is given much greater weight by the person who is affected. Rousing stories of war become scripture to warlike Vikings, Hebrews and Persians, vengeful stories of floods and supernatural murder are beloved by small insecure and endangered societies like Ancient Israel, medieval Europe etc., myths about fabulous rewards and divine sexy time appeal to poor patriarchal societies like Hindus and ancient Arabs, stories about eternal families and animals acting like humans gets matriarchal societies and groups on board like the women's instutute and so on.
This is the pattern for all religious writing , this is how the Book of Mormon, Dianetics, Genesis, Bhagvad Gita, The Shepherd of Hermas, Koran, Little Red Book, Epic of Gilgamesh, Beouwulf, Book of the Dead, Vol Popli and so on get written, accepted, believed and made sacred.