Well I don't know if you have to use Art like paintings and such... But the best example would be the Epic of Gilgamesh which is a book about a man who is 1/3 a god and goes on a quest for eternal life. The moral of the story is don't try to strive for something you cannot attain which is pretty pessimistic. Other features of the Culture revealed in the book are mentions of their different gods and their religious beliefs P.S. This is a VERY famous piece of literature.. I didnt just pull this out of some weird website. You learn about it in high school and college literature.