The following is an excerpt from the book 'Martin Luther's Theology: A Contemporary Interpretation' by Oswald Bayer:
For a long time already scholars have emphasized that the biblical texts are really to be considered as God's Word - as the living voice, the viva vox - only when they are preached, only hen presented in the oral fashion. To support this, words by Luther such as the following have been cited:
But that books even have to be written is already a great detriment and a weakness of the spirit, which have been forced by necessity, which is not the manner of the New Testament.
One notes that Christ did not write; instead, he spoke everything; the apostles wrote little; mostly, they spoke.
With such an exclusive emphasis on what is spoken, which follows Plato, it has not been noticed that Luther placed high value on written Word, as the source and deep foundational root of what was spoken aloud. Thus, in a sermon on 1 Corinthians 15:3-7, he emphasized that Paul explained the death and resurrection of Jesus Christ initially by referring to human witnesses, but then gave primary emphasis to "Scripture"
in order to guard against the raving spirits who disdain Scripture and external preaching and seek some other heavenly revelation instead, since such spirits swarm everywhere at the present, being unsettled by the devil, who see Scripture as a dead letter and praise only the Spirit and yet stay true either to the letter no the Spirit. But you can hear at this point how Saint Paul presents Scripture as the strongest witness and shows that there is no enduring value in considering our teaching and faith as[nothing but] the physical or written word, composed of letters of the alphabet and preached verbally by him [that is, Paul] or by anyone else. For it is stated here in a clear way: Scripture, Scripture. But Scripture is not merely Spirit, as they slobber, that the Spirit alone must make things happen, since Scripture is a dead letter and cannot grant life on its own. Instead, it says: Even though the letters cannot of themselves give life, it [that is, the physical or written Word] has to be there anyway and must be heard or received and the Holy Spirit must work through these very words on the heart, and the heart can hold on by means of the Word and be strengthened in the Word in faith against the devil and all temptation.
One can be sure that it was not only late in Luther's life that he rediscovered the meaning and the importance of what is scriptural. In the passage cited above from the 1522 sermon stating that books are needed because of "weakness of the spirit," he further declares:
Christ has two witness to his birth and his rule. One is Scripture or the Word, which is written using letters of the alphabet. The other is the voice or the words that are spoken out loud through the mouth.
And if it were helpful to express wishes, it would be the best of all to wish that, to put it bluntly, all books would be destroyed and that throughout the world, especially for Christians, nothing else would remain but the plain, pure Scripture or Bible."
The Bible as something that is in written form is thus identified as being more important than all other books. When it comes to understanding the gospel, the verbal proclamation is not given pride of place over against the written proclamation. Instead, faith enlightens both and unfaith darkens both - both the written Scripture and the words that are uttered verbally in the sermon. Scripture aim to make the verbal happen; but the verbal does not set itself up as a rival or as an alternative to what is written. "We also see in the apostles that all their sermons were nothing other than explicating Scripture and basing their message thereon." "There is no book that teaches the faith expect Scripture."
Thus, when it does come into being, faith begins in no other way than through the written words formed by letters of the alphabet, which have been transmitted in an impressive way in a form that one can trust, even though there are many inconsistencies in individual details, as has been determined on the basis of textual criticism. That which seeks to become new spirit and truth is ensconced in these alphabetic letters, empowered by the specific words to which God binds himself and lays aside his glory. But the new truth does not transcend the old. Instead, it returns to what is original to it and sets it in force again. God has given his oath, his word of honor, and that is not only transmitted in the letters of alphabet but is also transmitted to the letters, entrusted to them. One could also say: God has given his oath, his word of honor - in a testament. This testament has both a verbal and a written aspect. The verbal announcement of the resurrection of the Crucified One, of victory over sin, death, and hell, is itself based on a definitive Scripture, happening indeed "according to the Scripture," "in keeping with Scripture" (1 Cor. 15:3-4)
Setting it forth in written form is not setting it forth to develop a legal codification of iron-clad, forced, tyrannical articulated rules; in this sense Christianity is no religion of the book, as is Islam with its Koran. For the texts of the Bible cannot be rounded out to become a system. It would be more fitting to say they create a space - indeed, by means of definitive outer bounds that cannot be probed more deeply, though there are many gaps and empty spaces that allow freedom for the readers and hearers; but it does not establish an undefined freedom that would merely leave one frightened because no boundaries have been established. And yet one cannot come at it from the opposite side and maintain that one enters into a textual world in which everything matches up; one comes into a textual world where differences exist and where dissonant voices must be heard.
This is not pleasant. Time and again many have tried to smooth out what is rough, or at least to minimize such tensions. For example the theologically well-trained and sharp-minded church father Gregory of Nyssa wanted to make "the hard, indigestible bread of Scripture digestible" with unfettered allegorical interpretation. The hard bread of the lieral text is made digestible in that Gregory is drawn back to a sense that was known already: what makes one feel strange gets domesticated.
By contrast, Luther remained solidly against all this allegorizing by staying with the simple meaning of the Word, the literal sense - because of the clear meaning of the Word and because of the certainty of faith. If one lets the literal words stand as the "sure letter," as the sure prophetic Word (2 Peter 1:19), then one gives recognition to the watchman who stands guard for a strangeness that serves to communicate, which forgoes resolving differences so as to remain open and thereby establishes a relationship. In this way the letter serves the spirit and faith.
What is thus of utmost importance - over against Bible fundamentalism on the one hand and the charismatic movement on the other hand, which elevates the importance of itself over that of the literal text - is that one take seriously that a reciprocal relationship exists between that which is fixed and that which is changeable, between the verbal and the written, between the living Spirit and the fixed literal text. Whoever does not take this to be true misses the point about the unique character of the authority of Holy Scripture, which is none other than the authority of the living God himself. Luther took into account that what is fixed and what is open-ended both exist concurrently.