In a physical marathon, the "wall" shows up about mile twenty or twenty-one; when this happens, mind and body shake hands to say "we quit." That's where most runners will shut down, un they reach down into their identity as spirit. To the question "Who am I; what is my identity?" God's answer is "I am spirit; I have a mind; and I live in a body." So, to break through the "wall" requires a hierarchy of spirit over mind over body.
God's Word will address our spirit when mind and body are out of it, thereby setting Word over spirit over mind over body to keep the feet moving. Project this to other marathons: mental, spiritual, emotional, interpersonal, occupational, financial, etc.
Bottom line: Can the reader finish the book, put it down, and say: "Wow, look what God's Word performed; I want to be in the Word; I want the Word to be in me"? The closer the reader comes to God's Word, the closer they come to Him (John 1:14). The Word will have become "sent out (Isaiah 55:10-11), active and alive (Hebrews 4:12), watched over and performed" (Jeremiah 1:12) in their lives!