Perhaps I am over-interpreting your use of the term "summary" though. Do you mean something more like a "moral" or a "takeaway"? A summary, to me, is usually a brief restatement of the major points of a work, condensing examples and justifications to leave only the gist of the arguments or narrative arcs contained. In a summary of an anthology, I would normally expect to see at least a brief explanation of each of the books/articles it contains and their primary arguments. If preparing an edited volume, for instance, an editor wouldn't usually choose to describe only two of the articles it contains. Indeed, many published Bibles contain just such a summary at the head of each book, usually a feature of those referred to as "study bibles".
Yes. I suppose I should have used your offering, "takeaway."
I was attempting to find an overarching plot to explain all the subplots. Perhaps I could have used "salvation," but many who read and even adhere to their bibles will not achieve salvation.
It's similar to taking all the works of a given author and attempting to distill a very short statement of purpose, the bible being even more difficult because it has multiple authors over time, and all the inherent translation difficulties.
Maybe "The original guide to imperial christianity" would have worked.
