Here is the "nail in the coffin" IMHO.

We are subjective beings that must interpret from inside our skin. Practically speaking, one could claim to an have authority backing authority backing authority. However, once you get the the final authority (in this case Rome) one must still interpret the promulgations of that authority. We don't escape being in our own skin just because you have a magesterium. Would there be a need for canon lawyers in the Roman Catholic church if the edicts of Rome did not need interpreting?

Now, Rome will say that without the magesterium it is everyman, armed with a Bible, for himself. But this is throwing the baby out with the bathwater (in pedestrian terms) and not representative of what Protestant theology has historically taught about the role of the Church.

The Scriptures are not intended by God so that we could understand every doctrine perfectly...nor so we would not disagree with each other. However, they are entirely and utterly sufficient so that we can be made right with Him and be "thoroughly equipped for every good work".

__________________
Joel Batts
Christ Presbyterian Church (PCA) - Memphis, TN

"Why wasn't God watching? Why wasn't God listening? Why wasn't God there for Georgia Lee?"
- Tom Waits
But you, O God, do see trouble and grief;you consider it to take it in hand. The victim commits himself to you; you are the helper of the fatherless. - Psalm 10:14