The obvious literary precedent of God Knows is the King James Bible. Heller drew heavily upon events depicted in I and II Samuel and I Kings as inspiration for his narrative, although God Knows does contain scenes purely of the author's invention, such as David's visit to the Witch of Endor to consult with the shade of Moses. In Chapter One Heller acknowledges that the account of David in Chronicles little influenced his novel by having David exclaim, ". . . I hate Chronicles. In Chronicles I am a pious bore, as dull as dishwater and as preachy and insipid as that self-righteous Joan of Arc, and God knows I was never anything like that."

The King James Bible, however, is less important to Heller as a plot source than as a means of eliciting his readers' laughter, for much of the novel's comedy depends upon the contrast between...