Like other Faulkner novels, Light in August is kind of hard on religion. McEachern's strict Calvinistic beliefs leave no room for joy or fun, and seem to stifle individuality. The supposed gatekeeper of religion in the novel – Reverend Hightower – was defrocked due to his selfish, bombastic preaching style and his adulterous wife. Mr. Hines uses religion as an excuse to preach white supremacy. But, in contrast to these depictions, Byron Bunch doesn't advertise or preach, maintaining a quiet spirituality that sustains him throughout the novel.
In Light in August, Byron Bunch is sincerely spiritual, while Doc Hines and McEachern use religion in cruel and self-serving ways.
In Light in August, Faulkner argues that religion is used to justify racism.