A chiasm is a literary structure where vocabulary of the first section of a passage is repeated in reverse order in the second. The center of the chiasm is typically the climax of the passage. In John 10:19-39 the center and climax is Jesus saying to his opponents. “You do not believe because you are not of My sheep. My sheep hear My voice, and I know them, and they follow Me; and I give eternal life to them, and they will never perish; and no one will snatch them out of My hand” (John 10:26-28).