Thank you for taking your time to answer and for your suggestions.
I did a little searching and found nGram, but that doesn't seem quite the same thing.
The math on LanX's "tf-idf" option goes well over my head--to the point where it's not an option for me. (I got an "A" in college Calculus only by studying four hours for it every day, and asking peers lots of questions--but never really understood it, and it's all long gone from my memory.)
I'm sorely tempted to arrange for some access to a PostgreSQL DB just to try this. But how would one go about checking the similarity index for each verse? by iterating through the table 31,102-squared times? Does the DB generate the index on the fly? How could the results be efficiently stored? (I've never used indexes before, so I'm entirely unfamiliar with the process.)