In "By the Waters of Babylon," who is John and why does he set out on a journey?

John is the protagonist of Stephen Vincent Benét's "By the Waters of Babylon." As the son of a priest, John has a chance of being a priest, too. Priests have a lot of responsibility in John's tribe, which is west of the Place of the Gods. Going east to the Place of the Gods is not allowed, and, John claims, has "been forbidden since the beginning of time." 

Due to John's dreams and his ability to do the spells he is taught by his father and other priests, he is told he will be initiated as a priest. Before his initiation, John must go on a journey of discovery. At the beginning of his journey, John fasts and waits for a sign about where he is supposed to go on his journey. John sees an eagle flying east and takes that as a sign that he ought to journey to the Place of the Gods, even though it is forbidden. His journey to the Place of the Gods, which turns out to be an abandoned New York City, has a significant effect on John and the rest of his tribe.