And what are the apostles doing when they prove their own preachings by the Scriptures? Are they trying to obscure for us their own darkness with yet greater darkness? Or to prove something well known by something known less well? What is Christ doing in John 5[:39], where he tells the Jews to search the Scriptures because they bear witness to him? Is he trying to put them in doubt about faith in him? What are those people in Acts 17[:11] doing, who after hearing Paul were reading the Scriptures day and night to see if these things were so? Do not all these things prove that the apostles, like Christ himself, point us to the Scriptures as the very clearest witnesses to what they themselves say? What right have we, then, to make them obscure? I ask you, are these words of Scripture obscure or ambiguous: “God created heaven and earth”; “the Word became flesh”; and all those affirmations which the whole world has taken as articles of faith? And where have they been taken from? Isn’t it from the Scriptures?
And what is it that preachers do, to this very day? Do they interpret and expound the Scriptures? Yet if the Scripture they expound is uncertain, who can assure us that their exposition is certain? Another new exposition? And who will expound the exposition? At this rate we shall go on forever. In short, if Scripture is obscure or ambiguous, what point was there in God’s giving it to us? Are we not obscure and ambiguous enough without having our obscurity, ambiguity, and darkness augmented for us from heaven? What, then, will become of that word of the apostle. “All Scripture inspired by God is profitable for teaching, for reproof, for correction” [II Tim. 3:16]? Nay, Paul, it is not profitable at all, but the things you attribute to Scripture must be sought from the Fathers who have been approved for hundreds of years, and from the Roman See! So the statement must be revoked which you make in writing to Titus, that a bishop must be able to give instruction in sound doctrine and also to confute those who contradict it, and silence empty talkers and deceivers [Titus 1:9 ff.]. How can he, when you leave the Scriptures obscure to him, giving him, as it were, arms of tow and slender reeds for a sword? Then Christ, too, will have to recant, for he makes us a false promise when he says: “I will give you a mouth and wisdom, which none of your adversaries will be able to withstand” [Luke 21:15]. How will they not withstand when we oppose them with obscure and uncertain weapons? And why do you yourself, Erasmus, set out the nature of Christianity for us if the Scriptures are obscure to you?
But I fancy I have long since grown wearisome, even to dullards, by spending so much time and trouble on a matter that is so very clear. But that impudent and blasphemous saying that the Scriptures are obscure had to be overwhelmed in this way so that even you, my dear Erasmus, might realize what you are saying when you deny that Scripture is crystal clear. For you are bound to admit at the same time that all your saints whom you quote are much less crystal clear. For who is there to make us sure of their light if you make the Scriptures obscure? So those who deny that the Scriptures are quite clear and plain leave us nothing but darkness.
The Bondage of the Will
Luther’s Works Vol. 33