There is no link. Even illiterate people have a culture. Think of all the African Nations a 100 years ago. But the stories they tell, from the experience they had, is the literature of the next generation. And because they are verbally carried over, from memory, they grow, change, get embellished and become legends. To be retold and retold. Bigger, better and nicer. Literature, as we now know it, is changing perceptions, mostly to the detriment of the reader. Because "The Book" said so, it must be true. Wrong. You'll have to read x number of books and get/make/invent your own 'religion', your own set of values, your own truth.
Peace.