Discuss how the literary elements contribute to developing theme.
The arrangement of events, or plot, contributes directly to theme in O'Connor's "A Good Man is Hard to Find."
The disaster at the close of the story is a direct result of mishaps caused by the grandmother. She sneaks the cat into the car, and the cat causes the accident that strands the family. She makes the family search for a site that is actually in a different state. She blurts out the identity of the killer so he has no choice but to kill the entire family. She is ignorant, bigoted, stupid, stubborn, and closed-minded, and she costs the family their lives.
If you interpret the grandmother's reaction to the deaths and her threatened death as a conversion or epiphany, the plot points lead to her epiphany. Thus, the theme. The idea is that the mishaps she causes (plot) lead to her epiphany (theme).
The grandmother is a miserable human being who, if you see her epiphany as genuine (rather than as a ploy to talk the Misfit out of shooting her), finally becomes accepting of others, in her acceptance of the Misfit as one of her children.
The Misfit, then, is correct, of course. What she needed was somebody to hold a gun to her head everyday of her life. That was the only thing that could have made her a decent human being. And that's O'Connor's point. She sought to depict God's grace working in territory dominated by the devil, and believed violence was the only thing that would make people stop and think about God.