Book - John Steinbeck - East of Eden

I believe there is one story in the world, and only one, that has inspired and frightened us. Humans are caught—in their lives, in their thoughts, in their hungers and ambitions, in their greediness and cruelty, and in their kindness and generosity too—in a net of good and evil.

There is no other story A man will have only one question left at the end of his life: was it good or was it evil? And all novels, all poetry, are built on the never-ending contest in ourselves between good and evil.
East of Eden - John Steinbeck - Page V