John 16:12-13 I have yet many things to say unto you, but ye cannot bear them now. Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.
2 Timothy 3:16-17 All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, thoroughly furnished unto all good works.
2 Peter 1:19-21 We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts: Knowing this first, that no prophecy of the scripture is of any private interpretation. For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost.
I have a bit of a problem here in that I need to talk about three things all at once. It is difficult because all three things are different in form but are the same in their essential nature. It's like trying to pick out one side of an equilateral triangle and make it the first side. You can't do that because the three sides all support and reinforce each other. I'm not talking about the 'Holy Trinity' - that's something no one can explain with human reason. What I am going to talk about is the trinity of revelation, scripture, and authoritative teaching. These three things are distinct in form, but the same in their nature and support and reinforce each other.
There has been this ongoing cycle in the Church over the relative importance of each. The Catholics claim Church authority is primary. The Protestants will argue that "sola scriptura" is definitive. And then you have various Pentecostal, charismatic and mystical doctrines that claim only direct revelation is authoritative.
Now you would think it would be one or the other of the three, but really all three are correct. They are all correct because in the end they all must be the same thing. Stop for a minute and consider what the Bible is and how it was developed. Some of the books of the Bible are historical in content, but many are not. In either case, the point of historical records, prophetic writings, the poetry of the psalms, the wisdom books and the New Testament epistles all have in common the goal of teaching man the knowledge of God and His ways. That knowledge must come from a record of speech that begins with a man declaring what the word of God is. They don't claim to get that knowledge from prior writings alone but by direct inspiration. In other words, the Bible is a written record of direct revelation from God. There is no difference between the two other than when the revelation happened.
The books we have in the Bible are only a small subset of what has been written down. The contents are then a selection, which means, someone, sometime selected these books and rejected others. If we are to accept scripture as authority that implies we accept the authority of those who made the selection. Unless those who made the selection were under direct inspiration, the writings they selected must be considered questionable at best. Thus tradition and authority of Church councils is only authoritative for the same reason the Bible is held to be authoritative. Ultimately it is all by inspiration and revelation from God to man. The three - revelation, scripture, tradition - are sides of a triangle labeled "inspired by God." None of the three can claim to be primary anymore than one side of an equilateral triangle be said to be the most important side. I think it is useful to consider for a bit about why we have, and need, all three.
To start, we need revelation simply because of man's fall. Having fallen into separation from God by disobedience and rebellion, man lost the knowledge of the Creator. The only way to recover that knowledge is for God to intervene and reveal Himself to us. Judaism and Christianity both start with the assumption that God wants man to know Him and His ways and has thus revealed Himself for that purpose.
It is tempting to conclude that all we need is to have direct revelation and forget about anything else. Unfortunately there is a problem. Man in an unregenerate state is driven by carnal desires. It is all too common and all too easy to mistake those self-serving desires as a revelation from God. It is likewise common for man to seek a reasoned understanding of God using only man's mind. But, the reason of man can never fully comprehend or explain the infinite. Just as the heart can be deceived by vile affections, the mind also can be deceived by vain imaginings. We need something to support and validate what we perceive as a revelation from God. Sacred writings fill that need. We can compare our inspiration of the heart and mind against the accepted revelation of scripture and verify that it is correct.
This is precisely how we got a canon of scripture to begin with. In the early centuries of Christianity there were a variety of claims about what the Gospel meant, how salvation was to be understood, the nature of Christ, etc. The resulting divisions and continuous accusations of heresy among the Christians created a chaotic mess of Christian theology. In answer to that situation Church councils set up a rule (canon) to establish which books were to be read for instruction. The end result is the Christian Bible we have today (more or less).
With the recognized and authorized Bible in place, any question of dogma or questionable doctrine could be settled by appeal to the authority of scripture. Unfortunately, that is not a perfect solution. To begin with, books in the ancient world were comparatively rare and most people were illiterate in any case. Consequently, most believers had to rely on scholars and priests to tell them what the Bible said. Eventually the same deceitful carnal nature and limited human reason that necessitates scripture enters into interpretation of scripture. The Church authorities time and again became corrupt and made their own desires the only acceptable doctrine. Who could challenge them since they controlled not only what was authorized scripture but also what that scripture meant? Unless God intervenes and inspires some of the clergy, things never get corrected.
Eventually arguments over what traditions of the Church were valid and who would establish those traditions split the Christian Church apart. Initially there was the schism leading to the split between Roman Catholicism and Eastern Orthodoxy. In addition, the ancient Churches of the East and Africa were ignored. However, the greatest and most dramatic split was the result of the Protestant reformation in Europe.
This became one of the fundamentals of the Protestant reformation - sola scriptura. The attempt of the reformers was to rein in an out of control clergy by placing the scripture into a primary position over the traditions of Church councils and popes. In large part because of the invention of the printing press, the reformers were able to achieve considerable success. Unfortunately, their success split the Christian church into fragments of denominations that have never been reconciled since. Before long reform groups emerged everywhere in Europe. Each one had its own Bible and it's own interpretation of that Bible. The situation today is even more diverse with numerous translations of the Bible available. It seems as if we are back to square one - the same problem the Church faced in the third century.
In the end the reformers had to back-track (much to the amusement of some Roman Catholic theologians) and develop authoritative creeds and "confessions" that establish what the proper interpretation of the Bible should be. Nevertheless, the reliance on scripture alone has continued to dominate Christian theology outside the Roman Catholic and Orthodox churches into the twenty-first century.
Beginning in the nineteenth century a new force entered into the debate. With the development of scientific archaeology and the recovery of many ancient manuscripts, scholars began to have more data available for study. With every discovery came a new translation of the Bible and a plethora of new interpretations. Bible study quickly became a battleground between traditional and novel ideas. Furthermore, with the Bible now seen as a historical literary work and not simply as sacred writing, a whole field of secular interpretation (higher criticism) began as well.
In response, a group of ministers and laymen began an attempt to reestablish the "fundamentals" of Protestant Christianity. We know these as fundamentalists to this day. Their attempt at a defense against modern ideas was to treat the Bible in a very strict, often literal way, and limit translation and interpretation to what has been the accepted interpretation of the past. In a sense, they have done exactly what the earliest Church councils did - establish tradition as the touch stone to Bible study and eschew novel revelations.
Opposite the fundamentalists were the Pentecostals and Charismatics. Rather than return to the idea of accepted tradition, they sought to return all the way back to the origins of Christianity. Rather than continue to descend into ever increasing complexity of scholarly study, they sought out the experience of direct revelation from the Holy Spirit. And, as with the first century of Christianity, the lack of constraint of scripture and tradition results in a chaotic babble of self-appointed prophets and teachers. The more spectacular the claims, the more attention they get with the result that the whole movement descends to the level of a three-ring circus. Each group seeks to outdo the others in the number of miracles, healings, speaking in tongues, etc. We truly have come full circle.
All three sources of knowledge about God are valid and useful. No one of them, however, can be set up as the single definitive source. We need revelation to gain knowledge of God and we need direct inspiration to lead us in study of the Bible. Because of the complexity of translations, the need for knowledge of ancient languages and history, Bible interpretation must be supported by careful scholarship. Thus we use commentaries, writings of past preachers and teachers, respected current teachers, and determinations of councils as a guide to interpretation as well. All three must be inspired, of course. But, if inspired they will reinforce rather than contradict and thus provide a check against the wiles of the devil and the weakness of man's carnal nature. As a physical triangle is the strongest of physical forms due to the mutually reinforcing sides, in the same manner the combined use of revelation, scripture and traditional teaching is the strongest approach to understanding of God.