Usage of Symbolism in The Grapes of Wrath

The Grapes of Wrath is a novel chronicling the hardships endured by migrant families moving west to find a better life. In order to achieve the affect he wanted, John Steinbeck used an array of symbolism, from transcendentalism, to foreshadowing, to biblical allusions.
First, the main transcendentalist symbolism present in The Grapes of Wrath is in the character of Jim Casy. Casy is an ex-preacher who renounced his calling because of a sinful act he committed with a young girl after a religious meeting. "'…An' some I'd baptize to bring 'em to. An' then—you know what I'd do?…