From the Word
When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come.
John 16:13, RSV
When the Holy Spirit comes he will enlighten your hearts, so that you will understand the truth, and will call to remembrance all things. But our doctors and highly learned men have made use of these words in a most frivolous manner and said that it was necessary to have something more than the Scriptures, that one ought also to hear what the councils and the pope decree. They endeavor to prove in this way that Christ says: Because he has not told them all things, it follows that he told them to the councils, popes, and bishops.
Now look at these fools, what they say. To whom does Christ speak? Without doubt to the apostles. Therefore, if Christ is not to lie, his Word must have been fulfilled at the time that the Holy Spirit came. The Holy Spirit must have said everything to the apostles and accomplished everything that the Lord here refers to, and, of course, led them into all the truth. Christ gives to understand that soon the Holy Spirit would tell and explain to them all things, and that afterwards the apostles should carry out everything, and through them should be made known to the world what they have learned from the Holy Spirit. But according to the councils and popes it depends upon what they say, teach, and command, even to the end of the world.
If what the councils teach be the truth, that one is to wear the tonsure, and the cap, and live a life of celibacy, then the apostles never came to the truth, since none of them ever entered a cloister, nor kept any of those foolish laws. Christ must have indeed betrayed us in this, when he said the Holy Spirit should guide us into all truth, when in reality he wished to teach us how we were to become priests and monks and not to eat meat on certain days, and like foolish things. To hear such things is exasperating and it should grieve our hearts to see how shamefully the people act against the precious Word of God, and that they make the Holy Spirit a liar. Should not this single passage be powerful enough against the pope and the councils, even if we had no other in the Scriptures?
Luther, Martin, and John Sander. Devotional Readings from Luther’s Works for Every Day of the Year. Augustana Book Concern, 1915, pp. 191–92.