It is striking to me--and undoubtedly would horrify the modern antinomians--to see how clearly Luther upholds both salvation by grace alone and the life of good works done by the saved.
Your ways are not My ways.... Here He is speaking of ways by which we are justified. There are two ways. The one, by which we endeavor to prepare righteousness for ourselves and by which we go astray like sheep. The other is the way of God, which John prepared. This way is believing, trusting in God, hearing the Word, doing works prompted by the Spirit. This is the way of God. No one but the godly man can speak of it. The ungodly fall into their own …. Again they raise the objection: “It is true, He is speaking of bad ways, not of good ways.” But here You see Him speak indiscriminately, Your ways, all labors, endeavors, and merits, however solemnly undertaken. But the way of God, the work of God, is to believe in Christ. Thus He proceeds by way of dialog, so that they may not be afraid, that they may hear the Word while it is present, before the darkness comes. It is as if He were saying: “Dear children, there is nothing in you. You need My thoughts and ways. Be sure to observe what My ways and thoughts are.”Believing, trusting, hearing, and doing good works are all joined together. The works do not save ... and yet they follow (cf. Augsburg Confession, article VI).
(Bonus quote, unrelated but just so good: "Many think that they have faith when they have made a specter of faith for themselves, but when they meet danger, they slip. So the Sacramentarians babble with regard to the words of the Lord’s Supper, but they forsake the Word and labor with their own thoughts. 'In our thoughts and burning love we recall His suffering.” There, having forsaken the Word, they make a work for themselves. This is the true remembrance, to hear the Word of Christ. Thus all Sacramentarians and Anabaptists are Pelagians. Stay here with this text.' Don't you love that penultimate sentence?)