We do not disparage commentaries, study sheets, study Bibles and other such aids when we assert that they are not the word of God. They are useful, but in the end, if the teacher has studied these primarily, and not primarily studied the word of God, his teaching will be derivative. There are benefits to being derivative: it is usually safe, we need the wisdom of others, and we cannot understand everything ourselves. It is especially useful if we are mediocre students of the text of Scripture. But mediocre students will not make good teachers in the long run, and there are consequences to being mainly derivative.
Derivative teaching is teaching that is missing something. Something of freshness is missing, something of quality, even when what is told is all true, interesting and useful.
What is missing is the sense of a living encounter. When a teacher has studied the Bible, when he has pounded on the text like Luther, has wrestled with it like Jacob with God, refusing to leave until he has received something, when the teacher has done this, he comes to teach from a living encounter, an encounter that no other book can give or mediate. He comes, as it were, with something of a glow on his face from being in the presence of God.
In preaching and teaching the word of God, this, above all, is the quality to be desired.
Think about it, what else is at the heart of the idea that a preacher or a teacher has nothing of his own to say? He comes from the presence that gave the message. The word of God is like no other book, and when you go to study it, you go to encounter God. You come back with a better apprehension of his being. How can you come back from meeting God unaffected?
Holy Scripture does not mediate the word of God, it is the word of God. How can it be like understanding any other book? Of course you cannot bring a message if you don’t understand it, but it also makes a difference whether you receive it directly or mediated. It is the same message if it is mediated, but it is not the same messenger.
“I am Gabriel,” the messenger says to a dubious Zechariah, “that stand in the presence of God.” It carries its own authority, and the priest should have been sensible of it.
At the end of a life of being a preacher and aspiring to high ideals of preaching without considering himself to have attained them, but holding to high ideals nevertheless, Martyn Lloyd-Jones said very wisely that the aim of preaching was to give people a sense of having been in the presence of God. This, I think, is the heart of all our preaching and teaching in the congregation. A preacher conveys a sense of the presence of God by the power of the Holy Ghost, but he will not be visited with power from on high until he has met God in living encounter in the study of Scripture.
And this is why we must not be derivative teachers. Derivative teachers are mediocrities, and probably also boring if not interesting in all the wrong ways. We must learn from others, but internalize it. We must be better organized, but it has to grow from within. We must come to our teaching able to say that we have come from standing in the presence of God. If we are not able to do our study and use the commentaries for correction afterward, if our mainstay is not the word of God but the words of anybody else, we are still derivative teachers.