What are the motifs in The Life You Save May Be Your Own by Flannery O'Connor?

Nature and Its meaning is a recurring idea. "The Life You Save May Be Your Own" opens with a "piercing sunset" but ends with a "cloud descended . . . over the sun, and another, worse looking, crouched behind" the car driven by Shiftlet. A thunderous storm breaks; Shiftlet's eyes are "instantly clouded over with a mist of tears," and he feels "that the rottenness of the world was about to engulf him." The light and illumination of the sun has been replaced by a dangerous and threatening storm. These are two examples of O'Connor's use of natural imagery in this story.