What is the purpose of the last two paragraphs and explain how it contributes to the story's themes.
The last two paragraphs of the story, concerning Mrs. Hopewell and Mrs. Freeman, were added at the suggestion of O'Connor's editor.
Flannery O'Connor's "Good Country People" focuses on the story of a girl named Joy-Hulga Hopewell, who thinks that she is intellectually superior to those around her. Eventually, though, she is outwitted by an evil Bible salesman, Manley Pointer, who tricks her into removing her wooden leg, which he then steals.
O'Connor closes her story the way he started it with a conversation between Mrs. Hopewell and Mrs. Freeman, who watch Pointer escape. There comments hint at one of the themes in the story, namely that appearances can be deceiving. Mrs. Hopewell describes him as a "nice dull young man" and comments on his simplicity. She muses that "the world would be better off if we were all that simple.”
Of course, O'Connor's audience knows what these two women do not: that Manley Pointer is a crafty devil who was able to seduce a highly educated woman into taking off her wooden leg and then stealing it.
As Mrs. Freeman watches him run off, she concludes that she could never be as simple as someone like Manley Pointer. She is a simpleton, though, because she was unable to see through the treachery of this tricky Bible salesman.
Also betraying the two women's inability to see through Pointer's treachery is Mrs. Hopewell's assumption that he was selling Bibles "to the Negroes back in there". Mrs. Hopewell appears to assume that "the Negroes" were the sort of people who might be simple enough to be tricked into buying a Bible from him. Again, Mrs. Hopewell has judged Pointer incorrectly. He is anything but "good country people": he is the devil incarnate.