First and foremost, John is brave. He didn't run away when his father took him to the Dead Places. He didn't flinch when his father handed him a piece of metal. He takes his dangerous journey to the Place of the Gods in stride. He gets attacked by wild animals, yet doesn't panic. John is a brave guy. In a lot of ways, John is who many readers want to be like. Readers don't want to be associated with John's brothers. They were deemed too weak to be priests.
The other main characteristic about John is that he is curious. That's probably more important than bravery when considering Benet's narrator and story. John is curious about his world, and so is his reader. We, the audience, don't know if this story is in the future or the past. We don't know what these Dead Places are or what happened to all of the the people. Some of it is familiar, but much of it just seems weird. We are genuinely curious to find out more. And so is John. John wants to go on his journey. He wants to go to the east. He wants to go to the Place of Gods, and readers want him to do it, too. That way, John and we can learn together.
What does John learn? John learns that there is great value in past knowledge. He is saddened by how much knowledge was lost. It's good that John tells us his story, because it reminds us that the past is important. It reminds us to not think that learning and knowledge is trivial. It reminds us that we must actively seek to store our wisdom from generation to generation.