Controversies over Christian Faith – From Within

I found myself compelled to respond to a comment on another blog discussing Progressive Christianity… whether or not it is dying (and should at least be pronounced terminal).
The article, satirizing an anti-progressive one, I found clever and provocative. Discussion was extensive. After posting a couple comments, I realized the second one is a crucial enough point, in itself, to be worth posting on my own blog. So here it is, with only minimal editing:
It amazes me how people use the biblical phrase “…faith once for all delivered to the saints.” Exactly what was “delivered”? And when was the “once”? And how was it delivered? And just who were “the saints” referred to? Both scholars and lay people can use canonical Scripture (itself a very dicey concept, but accepted here for sake of argument) to legitimately answer these questions in very different ways.
For example, though less common in recent decades, it wasn’t that long ago that Protestants and Roman Catholics, in general, gave very different descriptions of what WAS that “faith once for all…” Means of salvation, authority of tradition/church leaders, and much more seen very much in opposition. And that’s not even touching arguments within both Protestant and RCC branches, orders, denominations, etc. Shouldn’t surprise us, though….
The reason the NT can be used to argue quite different theologies is that the NT authors themselves were not operating from anything close to a unified, widely accepted, “delivered” set of beliefs or priorities, despite the claim of Jude.