Jim Casy's 'prayer'

Jim Casy's 'prayer' was more his thoughts on holyness than anything else. Granma was saying things like "Hallelujah" and everyone was waiting for Casy to say Amen. Steinback wrote that this was just because everyone was used to waiting and Granma had just "timed her responses to the pauses".
Does the prayer and how the family acts have symbolism? Does it say something more about Steinback's religious beliefs?

Jim Casy's prayer p.109-111