Today conservative Protestant exegetes typically use an analytical method of determining the meaning of Scripture by grammatical and linguistic methods and a comparison of Scriptures. Scripture interprets Scripture, and clear Scripture interprets unclear Scripture.
Two problems arise. One is that in reading the Early Church Fathers, the first method is never used by them. It cannot then be said that in any way this method is of value in recovering a so-called “lost” early Christianity, as the method is, I think, post- Enlightenment without any historical basis. The insistence upon the part of some that this is the right method to determine or recover correct theology is contradictory to its historical absence: how could God have expected the early Church to use a method of Scriptural interpretation that did not arrive for over a thousand years?
The second is that in order for clear Scripture to interpret unclear Scripture, one must find clear Scripture, that is, without ambiguous meaning. The problem there is that one must be selective, as I have seen different people insist certain Scriptures are clearly proving one thing while others insist those Scriptures are unclear, and those others present other Scriptures as clear, which the first group then rejects as clear.
So I think if someone is going to be insistent on recovering early Christianity, he must insist on using approaches employed by the early church, including typological and allegorical approaches which are prevalent in the ECF, in contrast to the modern linguistic analysis some are fond of.
Foundational differences in Scriptural interpretation techniques seem to lie at the bottom of our ability to reconcile Catholic and Protestant theological differences. While this is not the only problem, it is a significant one.
Just a thought.