I have called this second-tier element, for lack of a better term, a theological mediator. A theological mediator may be a person (living or dead) or an institution. And to the best of my knowledge every church/denomination/movement in history has had one.
Generally speaking, a theological mediator unites believers by doing two things:
- Applying (or "mediating") Scripture in a message that is particularly applicable to their current circumstances.
- Demonstrating supernatural confirmation that their message is from God.
But the definition of theological mediator must not exclude those in other churches who fulfill similar roles. For example, Protestant churches recognize the work of the Holy Spirit in generating the reformers messages, and thus Wesley functions as a theological mediator for Methodists, Calvin for Calvinists, etc. Granted, they do not recognize as strong a supernatural confermation in the experience of their reformers as Adventists see in Ellen White, and perhaps this is why their churches are less organizationally unified.
The Roman Catholic Church, on the other hand, is very organizationally unified, and has developed a theological mediator with a supernatural confirmation of prophetic proportions. According to the Catechism of the Catholic Church the Pope, when he makes certain proclamations (ex cathedra), and his bishops, when they all get together and make proclamations, are infallible in matters of doctrine and practice (Section 891). This is accomplished by means of a spiritual gift, "the charism of infallibility," and has a "prophetic" function in the church (Sections 2035-6).
So when critics of Adventism say that Ellen White is like the Pope, in a certain sense, they are correct. But if they stop there and do not acknowledge certain key differences between the way the pope functions as a theological mediator and the way Ellen White functions as a theological mediator (like their relationship to scripture), they are not doing justice to either. But the conflation of Ellen White and the Pope serves to illuminate the underlying issue with these critics ignore, which is that they prefer their theological mediators (such as Luther) on the lower end of the supernatural confirmation spectrum.
I hope by now it is clear that, on a practical level, the question is not so much whether we will have theological mediators, but who or what we will allow to occupy that position in our theology. I believe that ideally each individual should make up their own mind based on the other four elements of the quadrilateral in proper relation to each other. In reality, few Christians ever undertake such a radical questioning of their belief system of their own accord.
One final note for Adventists: I have "Spirit of Prophecy" in the chart and not "Ellen White" for a reason. If we limit the Spirit of Prophecy the institution of Ellen White's writings, we cut ourselves off from the possibility of a living prophet, and the relevance of our message will soon pass beyond the horizon of relevance in our changing world. I'm not asking us to accept every Ernie Knoll that comes along, but we must be open to the larger fulfillment of Joel 2 if we want to be the remnant of Revelation 12.