In "By the Waters of Babylon" how is the first-person point-of-view an advantage to the reader?

The first-person point-of-view is incredibly helpful to
the reader in this story, because John lives in a world that is not our time period, and
in a culture that is very unusual and foreign to us.  John is able to explain, through
his narrative and thoughts, many aspects of that culture, as a first-hand witness who
lives it each and every day.

Also, because John is a
priest, he is privileged to know things about their world that other members of the
tribe would not have; getting things from his personal perspective opens us up to a lot
of information that we would not have known otherwise.

The
first-person perspective also allows us to understand John's thoughts as he goes on his
long, lonely spirit walk to the Place of the Gods. Without the first-person narration,
all we would see is John walking, and know nothing about his dreams, his fears, his
hopes, and his own personal interpretations of
things.

Lastly, the first-person narrative makes it feel
more like a story that is told and passed down from generation to generation.  This is a
tradition of all ancient cultures; they didn't write things down, they told the stories
to one another.  The first-person narration makes us feel like we are sitting around the
campfire with him, listening to him tell the story for the first time.  We get his spin
on it, his wise perspective, and his fresh eyes as he journeys, and all of it is told as
if he were speaking directly to us.  That makes it more personal, relatable, and also in
sync with the culture that he came from.

I hope that helps
a bit; good luck!