The more I thought about this, the less sense it made to me.I am agreeing with what I believe is a powerful analysis that assigns the definition of "essential" and "core" to certain commonalities precisely because of the fact that they are found in all religions throughout history.
Suppose someone compiled a list of commonalities found in all fantasy fiction (which would presumably include Tolkien's LoTR). Now suppose someone were to say that those commonalities exclusively define what is essential and core to, what are the only worthwhile aspects of any work of fantasy fiction. Is that an idea many of us would agree makes sense?
It makes more sense to me that some of the unique aspects of LoTR -- the things one doesn't find in other works of fantasy fiction -- are more important aspects of the work, at least for some of us, are what we consider the essential and core aspects of the work that make it special to us. Generally speaking, isn't it possible if not likely, that the unique qualities of a thing are at least as essential and core to its being as its generic qualities?
In other words, shouldn't the thing about a work -- or a faith -- that sets it apart from, as opposed to the things that make it the same as others of its kind, be viewed as at least as, if not more, definitive of its essence and core?
Of what else besides belief systems, would we accept that only its generic aspects are of value? It seems counter-intuitive to me.
Let's take politics. What if I used the same lowest common denomenator theory and reduced both the basics of the Republican Party's and the Democratic Party's apparent goals to the generic values they share as parties in the American political system, so that I ended up with one platform of the things they can both agree on. I would have very few actual policies and lots of rhetorical pablum. And wouldn't I essentially be taking Ralph Nader's line, that between the two parties, it doesn't matter who we elect because the essentials are the same? Yet we know (many of us would agree) that it matters a great deal who we elect. Because the particulars matter. The particulars define. The particulars have an effect on our quality of life. The particulars represent real, important differences.
So this idea, if I've got it correctly -- that the generic ideas shared by all the world's religions are the only important ones, are exclusively representative of the essence and core of each of the individual religions because of the fact they are found in all of them -- seems a little off to me.