God will uphold you with His victorious right hand.

I will uphold you with My victorious right hand. This beautifully brings the supreme comfort to a close. He uses a new word, I will uphold you. Christ grants the strength of His own righteousness to all believers and descends on the wretchedness of all who rely on their righteousnesses. Therefore he says here: “Only the righteousness of Christ, which is His own, this alone helps you against all enemies.” There he indicates that the Christian man is especially distressed by his own righteousnesses or is even perplexed by sins, his own and those of others and false ones. Day and night Satan is busy making sinners afraid, and with endless devices he assails this citadel, a happy conscience. That is something he cannot endure. But Christ fortifies this citadel against all the assaults and endless schemes of Satan. “Do not be confused, do not fear sins, and do not rely on your righteousness, but walk the middle way. Grasp My righteousness, and cling to it alone.”

Martin Luther
Luther’s Works Vol. 17 Lectures on Isaiah Chapters 40-66

Their works are nothing but grasshoppers. . .

This comparison with grasshoppers is frequently used in the Scriptures, as if to say, “Grasshoppers are easily shooed away.” All inhabitants of the earth are like this in the sight of God. They cannot bear God’s least judgment but are scattered by one word and breath of God. So today we observe that the pope and all the most holy servants of the Mass are in God’s sight nothing but grasshoppers that are scattered. The nations, again, are not to be understood metaphysically. The reference is to every undertaking and righteousness on their part that aims at appeasing God. Their works are nothing but grasshoppers that must be dispersed. And they hang on very weakly.

Martin Luther
Luther’s Works Vol. 17: Lectures on Isaiah Chapters 40-66

The gist of preaching is “Behold your God.”

Say to the cities of Judah: Behold your God! He mentions the doctrine that should be preached. This is the gist of your preaching: Behold your God! “Promote God alone, His mercy and grace. Preach Me alone.” The rest, the ungodly, preach the doctrines and works of men, their own rules and righteousnesses. This herald must avoid that kind of teaching and speak of Christ alone. In Him alone rests all our salvation.

Martin Luther
Luther’s Works Vol. 17: Lectures on Isaiah Chapters 40-66

Luther on Isaiah 40:2

2. Speak tenderly to Jerusalem.

So here, the heart, groaning and sighing, is comforted by the Spirit, for the Spirit speaks to the heart as He wills. Do you want a gracious God? He answers: “You have a gracious God.” Do you want to be comforted? He answers: “You are comforted.” Here, then, you observe God’s people, afflicted and sad. To them the Gospel is spoken, to their heart and feeling. For Gospel preachers are commanded to say joyful things, more than the heart can grasp, as Paul says (Rom. 8:26), “with sighs too deep for words.” So these groans are comforted with consolations too deep for words. Let the preacher say, then: “I not only preach Christ to you as the One who forgives, but I also give you His righteousness, so that, clothed with Him, you may have all that is His. The comfort is therefore far more excellent than all groanings. Do you want to be holy? I will make you holy, yes, most holy through Christ.”

Martin Luther
Luther’s Works Vol. 17: Lectures on Isaiah Chapters 40-66

Johann Gerhard on The End Effect of Scripture in Respect to God

With respect to God, the end of Scripture is the salutary knowledge and glorification of God. It is for this purpose that God revealed Himself in His Word that was first spoken orally and later was committed to writing so that He, having been known correctly by human beings according to His essence and will, might be praised in this life and in eternal life. When we recognize from the Word of God His goodness, power, and wisdom and when we meditate devoutly on the mystery of our salvation that has been planned from eternity and revealed in time, that we cannot help but be stirred by that knowledge and meditation into a love for God. From this love there immediately arises in our hearts a celebration and glorification of the supreme good.

Johann Gerhard
On the Nature of Theology and on Scripture
p 328

Johann Gerhard on the authentic text of Scripture

§ 316 …

In De verbo Dei, bk. 2, c. 10, Bellarmine burdens us in this controversy with a double calumny: “(1) That we consider only Luther’s version authentic; (2) that we disagree not a little bith in choosing an authentic Latin version.” However, we claim the Latin or German version of neither Luther nor anyone else as authentic, but only the Hebrew text in the Old Testament and the Greek in the New.

Johann Gerhard
On the Nature of Theology and on Scripture
p 282

Johann Gerhard on what the Apocryphal Books of the New Testament teach us

§ 304 Furthermore, this multitude of apocryphal writings that heretics have spread under the venerable names of the evangelists and apostles teach us: (1) About the devil’s great hatred against the sacred writing, who has intended in various ways to gain canonical authority for apocryphal fables and, on the other hand, to bring the sacred, divinely inspired, and truly canonical books into contempt. (2) About the matchless providence of God by which it has happened that the canon of the New Testament was preserved whole and inviolate. Consequently, God granted a long life to St. John so that he might be able to teach the Church about the genuine, canonical books of the evangelists and apostles and to distinguish them from spurious and fictional works. (3) About the devout concern and faithful care of early antiquity in distinguishing apocryphal and spurious books from the canon.

Johann Gerhard
On the Nature of Theology and on Scripture
p 271