Only he is an orthodox teacher who not only presents all the articles of faith in accordance with Scripture, but also rightly distinguished from each other the Law and the Gospel.
Suppose some one could truthfully say, “There was no false teaching in my sermon,” still his entire sermon may have been wrong. Can that be true? The second part of our thesis says so.
Only he is an orthodox teacher who, in addition to other requirements, rightly distinguishes Law and Gospel from each other. That is the final test of a proper sermon. The value of a sermon depends not only on this, that every statement in it be taken from the Word of God and be in agreement with the same, but also on this, whether Law and Gospel have been rightly divided. Of the same building materials furnished two architects one will construct a magnificent building, while the other, using the same materials, makes a botch of of it. Crack-brained man that he is, he may want to begin at the roof or place all windows in one room or pile up layers of stone or brick in such a fashion that a crooked wall will be the result. The one house will be out of plumb and such a bungling piece of work that it will collapse while the other stands firm and is a habitable and pleasant abode.
Zechariah relates the following, chap. 11, 7: I will feed the flock of slaughter, even you, O poor of the flock. And I took unto me two staves; the one I called Beauty, and the other I called Bands; and I fed the flock. A real, spiritual shepherd has two staves, or rods. The rod Beauty is the Gospel, and the rod Bands is the Law. He must be well informed as to the persons to whom he is to apply either the one or the other of these staves. The Messiah — who is the Speaker in this passage — says that He used the rod Bands against the flock of slaughter, that is, against sheep which were to be slaughtered and not to be led to the pasture. The “poor of the flock” represent poor sinners. Among them He uses the comforting staff and rod of the Gospel. Most preachers make the mistake of hurling the rod Bands among the sheep and using the rod Beauty for wicked knaves.
(By the way, Luther’s translation of this passage is unexcelled. Would that the people who want to revise Luther’s Bible would stick to their private affairs!)