The book of lights.

Gershon Loran is a young rabbi, the product of a parochial New York Jewish upbringing -- whose early life [was] shaped by darkly irrational circumstances. He is this young man raised in the absolute belief that 'the Jewish religion made a fundamental difference in the world' who at the end of the Korean War, finds himself a chaplain in a country where Judaism has played no part. Gershon begins to see his own people, and himself, in a new light. Gershon has the most disturbing of his visions encompassing both light and dark, both good and evil, just as life must; just as, he begins to understand, Judaism must, if it is to remain a living faith.