What is the theme in The Story of B by Daniel Quinn?

One of the most important themes in this novel are B's teachings. These are best exemplified by his public teachings at the end of the novel, though his private teachings are also important. In Der Bau, Munich, on May 16, B lectures on the Great Forgetting. It is strange that the educational and character-shaping structures of culture exposes people only once to the masters but continually to religion. It is necessary for B to repeat himself many times.