Final answer:
Red Sammy starts the conversation by talking about his suspicion that a couple of individuals recently stole gasoline from him, reflecting the theme of the difficulty in finding 'good' people.
Step-by-step explanation:
In Flannery O'Connor's short story "A Good Man is Hard to Find," when the Grandmother and her family first meet Red Sammy, the first topic of conversation that he brings up is about a recent encounter he had with individuals who, he believes, likely stole some gasoline from him.
This interaction sets the tone for the theme of the story as it explores the difficulty of determining who is 'good' in a morally ambiguous world.
Red Sammy's lamentation about the challenge in trusting people serves as foreshadowing for the family's later encounter with the Misfit.