The biography of Flannery O’Connor is definitely relevant to understanding her short story "Revelation." O'Connor was from the same geographic region that she is writing about in the story, the American South, and many of the themes of this story, such as racism, were social issues of the day that she observed around her. At the time, many racist white Americans were struggling to coexist with the social status of black Americans, who were no longer enslaved but faced Jim Crow discrimination nonetheless.
In addition, O'Connor suffered from the disease Lupus, an autoimmune condition which she eventually died from at age 39. O'Connor's disability created a difference in herself from able-bodied people, much like her character Mary Grace, who is described as physically and mentally different from other characters. Thus the disability of Mary Grace can be understood from the lens of O’Connor’s own experience with disability. While Mary Grace seems a grotesque character at first—rude, ugly, and mean—she can also be understood as a statement on difference in general. In light of O'Connor's personal disability, the disability of Mary Grace may be viewed by readers from a more nuanced or sympathetic light.
Finally, O'Connor's Catholic faith is reflected in the story as the character Mrs. Turpin has a vision at the end of the story of people ascending to heaven, and the title of the short story—Revelation—is also the title of a book in the Bible (Revelations).