Theron Ware is a promising young Methodist pastor recently assigned to a congregation is small town in the Adirondack Mountains. His education has been limited and his experiences limited to church society and his strict enforcement of its norms.

Theron has a number of experiences that cause him to begin to question the Methodist religion, his role as a minister and the existence of God. His "illumination" consists of his awakening to new intellectual and artistic experiences embodied by several of his new acquaintances including the town's Catholic priest who introduces him to the latest Biblical scholarship; a local man of science, who eschews religion and advocates for Darwin; and a local Irish Catholic girl with musical talent and artistic pretensions, with whom Theron becomes infatuated.