Authority & the Interpretation of Scripture

Remarking recently on his understanding of James' doctrine of justification, nuclear physicist and insightful commentor on Reformed theology, David Heddle of He Lives, wrote, "I believe in sola fide because I think, taking scripture as a whole, it is overwhelmingly and clearly taught."

I'd like to use David's statement as the launching pad for some brief comments on authoritative Scripture interpretation.

Actually, they will be quite brief. Essentially, my question is this: when two intelligent and devout Christians have different (even opposite) understandings of what Scripture teaches, what is one to do? In this case, David states that he is convinced that sola fide is the biblical doctrine of justification. But I am just as convinced that it is not. Now what?

If there is no authoritative interpreter of Sacred Scripture, we are at an impasse; we have two devout believers, both of whom are convinced that their doctrine is the biblical one. Each will make his case to the other, but chances are, in the end each will remain sure of his position. (Of course, sometimes one side realizes their error, but this is fairly rare.)

Is this what God intended? That people whose interpretations differ would have no recourse to a divinely-established and -protected authority to resove their differences? Perhaps. But I don't think that this is the case. It seems to me that the Catholic argument that God has in fact established the Church as the definitive interpreter of Scripture makes complete sense (and I also think [naturally] that Scripture supports this claim, but that's exactly what this is all about).

To me, the question of Authority is the question in apologetical and ecumenical dialogue. Not that it is the most important one, but that it is the key to the rest. If we could come to an agreement on the true nature of ecclesial authority, it would be that much easier to resolve our other differences. IMHO.