Luther had a “living voice” of the Gospel concept that is fascinating. No one loved the Bible more or studied it harder, but Preaching was for him a voice declaring and proclaiming in a living confrontation with a hearer the marvelous mercy of God.
Here he is……
In the New Testament the sermons are to be spoken aloud in public and to bring forth in terms of speech and hearing what was formerly hidden in the letter and in secret vision. Forasmuch as the New Testament is nothing else but the unlocking and revealing of the Old Testament … that, too, is why Christ Himself did not write His teaching, as Moses did his, but delivered it orally and gave no command to write it. … For that reason it is not at all the manner of the New Testament to write books of Christian doctrine, but there should every where, without books, be good, learned, spiritually-minded diligent preachers to draw the living word from the ancient Scriptures and constantly bring it to life before the people, as the Apostles did. For before ever they wrote, they had preached to and converted the people by word of mouth, which also was their real apostolic and New Testament work. . . . That books had to be written, however, is at once a great failure and a weakness of spirit that was enforced by necessity and not by the manner of the New Testament.
