SECTION III. A TRUE PREACHER SHOULD FIRST USE THE LAW ARIGHT AND THEN PREACH THE GOSPEL.
9. The porter here is the preacher who rightly teaches the Law–shows that the Law exists and must reveal to us our helplessness; that the works of the Law do not help us, and yet they are insistent. He then opens to the shepherd, that is, to Christ the Lord, and lets him alone feed the sheep. For the office of the Law is at an end; it has accomplished its mission of revealing to the heart its sins until it is completely humbled. Then Christ comes and makes a lamb out of the sheep–feeds it with his Gospel and directs it how to regain cheer for the heart so hopelessly troubled and crushed by the Law.
10. The lamb then hears Christ’s voice and follows it. It has the choicest of pastures, and knows the voice of the shepherd. But the voice of a stranger it never hears and never follows. Just as soon as one preaches to it about works, it is worried and its heart cannot receive the teaching with joy. It knows very well that nothing is accomplished by means of works; for one may do as much as he will, still he carries a heavy spirit and he thinks he has not done enough, nor done rightly. But when the Gospel comes–the voice of the shepherd–it says: God gave to the world his only Son, that all who believe on him should not perish, but have everlasting life. Then is the heart happy; it feeds upon these words and finds them good. The lamb has found its satisfying pasture; it wants none other. Yea, when it is given other pasture, it flees from it and will not feed therein. This pasture always attracts the sheep, and the sheep also find it. God says in the prophecy of Isaiah: "So shall my Word be that goeth forth out of my mouth: it shall not return unto me void, but it shall accomplish all in the things whereto, I sent it" (Is 55:11).
SECTION IV. THE HEARERS HAVE THE RIGHT TO EXAMINE AND JUDGE A SERMON
"And he calleth his own sheep by name, and leadeth them out. When he hath put forth all his own, he goeth before them and the sheep follow him; for they know his voice. And a stranger will they not follow, but will flee from him; for they know not the voice of strangers."
11. In this text there are two thoughts worthy of note: the liberty of faith, and the power to judge. You know that our soul-murderers have proposed to us that what the councils and the learned doctors decide and decree, that we should accept, and not judge for ourselves whether it is right or not. They have become so certain of the infallibility of the councils and doctors that they have now established the edict, publicly seen, that if we do not accept what they say, we are put under the ban. Now, let us take a spear in hand and make a hole in their shield; yea, their resolutions shall be a spider’s web. And you should, moreover, use upon them the spear which until now they have used upon us, and hold before them its point.
12. Remember well that the sheep have to pass judgment upon that which is placed before them. They should say: We have Christ as our Lord and prefer his Word to the words of any man or to those of the angels of darkness. We want to examine and judge for ourselves whether the pope, the bishops and their followers do right or not. For Christ says here that the sheep judge and know which is the right voice and which is not. Now let them come along. Have they decreed anything? We will examine whether it is right, and according to our own judgment interpret that which is a private affair for each individual Christian, knowing that the authority to do this is not human, but divine. Even the real sheep flee from a stranger and hold to the voice of their shepherd.
– Volume III of, The Sermons of Martin Luther