The setting seems like it takes place in the time before civilization advanced through industrialization. People seems primitive by our standards and very superstitious as well. Events are referred to with descriptive terms instead of names, such as the City of the Dead, the bitter waters, the gods, and the Great Burning. Clearly, these are not educated people, but hunter gatherer societies. Priests are the only ones allowed to go certain places and do certain things, like enter the city of the dead and touch metal. They are taught chants and words to keep them safe from the spirits. Just enough details keep the reader intrigued by references to things that people of such a primitive nature would not have or know.
John, though primitive by our standards of knowledge today, has enough learning to make him challenge the forbidden things in his culture. His inquisitive nature and the fire in his mind and heart make him a character that will advance or die trying. He is prepared to die for his violations of the forbidden, but he pushes on. He is both courageous and far-seeing.