"The Diamond as Big as the Ritz" is full of religious and mythological allusions, touching on everything from the Bible to Ancient Greek gods. Fitzgerald's story argues that, in America, religion has been replaced by wealth. In other words, Americans worship money, not God. Through very particular stylistic and tonal choices, Fitzgerald gives his story an element of timelessness; it reads like a myth itself. This suggests that the problems satirized in the story are timeless in themselves. Fitzgerald criticizes wealth, and so there an allusion to King Midas. He satirizes man's unstoppable, often destructive desire to reach higher grounds, and so references the mythical figure Prometheus.
"The Diamond as Big as the Ritz" is presented in the style of a mythological tale, not a modern short story.
"The Diamond as Big as the Ritz" argues that America has abandoned God.