Who is the authoritative interpreter of the Christian faith? Where does authority reside?
The authoritative interpreter is clear for the Catholic Church. I believe most evangelical Protestants would say their authority rests on the bible alone. “On the solid word I stand all other ground is sinking sand.”
As early as the reformation the scripture was being divided into primary and secondary themes. Primary themes are those themes determined central to the Christian faith. Secondary themes are those where there can be disagreement.
If the process of determining the central core values and principles is successfully executed I would hope the outcome would be a view of the Christian faith and what it means to be the people of God that would have contemporary and historical consensus. And it would prove unifying for the people of God regardless of denominational stripe.
Each generation of believers does in fact re-read both the scripture and its application to determine in their specific context what being a follower of Jesus means. I see no way to escape diversity. This process of contextualization however does not mean that whatever I believe is authoritative.
Some fences can be reasonably established based on the multi-generational understanding of the core values of the Christian faith but the line does seem to move and swing. Since I do believe the bible is in fact authoritative with respect to faith and godliness I feel it important to establish a reasoned approach to what good and bad interpretation of the bible is. But at the same time I recognize that we cannot easily escape cultural influences that in turn shape the theological reflection and its application.
The 17c and 18c did put the Church on a path that expects our faith to be reasonable and subject to reason. At the same time Pietism seems to have made it impossible to escape the individual’s responsibility toward the process.
This creates a tension around certainty. A scholastic and top down authoritative approach does reduce the tension. In this respect the value of the doctrine of Papal Infallibility does provide a form of relief. It is a much simpler execution of faith if you can pass the responsibility for determining matters of morality and Christian practice to another.
In a way my faith requires more faith to move forward. I have to have confidence that God is larger than the scope of my uncertain certainties and my trust in another must be Him.