What separates life from death? Minutes? Seconds? Our minds? "An Occurrence at Owl Creek Bridge" doesn't give us a definitive answer, but it does complicate and explore issues of consciousness, awareness, dying, and the afterlife. Anyone who finishes reading the story knows that Farquhar is dead. But they also know that he seemed to do a great deal of living in the seconds between hanging and death. Overall, the theme of death is deeply related to that of time and versions of reality in this story, because the experience of the separation between life and death is super subjective for Farquhar.
Death and life are very separated from each other. It is only Farquhar's imagination that connects them.
Life and death are very closely linked, and Farquhar's death proves how easy it is to mistake one for the other.