The image to the left is a product of Chris Harrison which maps 63,000 Bible cross references. His aim was simply to visualize the relationship of the text, forgoing functional possibilities for the simple aesthetics of what the cross reference create.
"The bar graph that runs along the bottom represents all of the chapters in the Bible. Books alternate in color between white and light gray. The length of each bar denotes the number of verses in the chapter. Each of the 63,779 cross references found in the Bible is depicted by a single arc - the color corresponds to the distance between the two chapters, creating a rainbow-like effect". Chris Harrison Website
I referenced the very same subject matter for content for a course in information design. My goal was to find a way to visualize various relationships presented in scripture so that meaning would be revealed to the viewer. Unlike Mr. Harrison my aim was to produce a functional tool for understanding.