Those are the words of Brenz.
In what way salutary and divine effects are attributed to the Gospel.
§ 47. Furthermore, these are the salutary effects of the Gospel: that it provides reconciliation with God, remission of sins, righteousness, peace of conscience, and eternal life. They are attributed to the Gospel only with respect to its instrumental cause. Indeed, the efficacy of the doctrine of the Gospel depends on the work of the Holy Spirit, who is efficacious in people’s hearts through the word of the Gospel. Just as manna fell with the dew (Exod. 16:[14–15]), so also the dew of divine grace is conjoined with the manna of the doctrine of the Gospel (Isa. 55:10). That is why the Gospel is called “the power of God unto salvation for all who believe” (Rom. 1:16); “the word of the cross,” that is, the Gospel of Christ crucified, “is the power of God to those who are being saved” (1 Cor. 1:[18]). In the same sense and respect it is called “the scepter of divine power” (Ps. 110:2).
It really is the living and efficacious instrument of divine power through which Christ administers His kingdom of grace in the hearts of those who believe, in regard to which I shall make note of a very beautiful comparison of Dr. Brenz (Confess. Witebergens., chapter De evangelio, p. 407):
When we say that the Gospel is the joyful declaration concerning the Son of God, we are not speaking about the letters and syllables with which the words of the Gospel are either contained on paper or spoken aloud outside their proper, legitimate, and ordinary use. For even if the Gospel were put into writing for this purpose, that it might be drawn from them as if from a storehouse at its own time and for its own use, yet outside its own office the Gospel is not of itself sad or joyful; it neither kills nor gives life. Rather, we are speaking about the declaration of the Gospel, as it is in its proper, legitimate, and ordinary office and use for which it has been divinely established. In the account of Esther, we have an edict that if anyone, either man or woman, should enter uninvited the inner chamber of the king, he is to be killed immediately unless the king by chance should reach out his golden scepter to him as a sign of clemency [Esther 5:2]. Although this scepter was made of gold, yet it offered no one any safety of life of itself or closed up in a display case or locked up in a box. But if the king should take it in his hand and stretch it out toward one who was entering, then it was being used legitimately and with its touch would save the person entering from the king’s guards. The same thing must be recognized about the Gospel, that when it is contained merely in letters, or even is proclaimed or announced orally, or even is thought of according to its legitimate purpose, then it is truly the heavenly instrument by which the Holy Spirit works salvation in His elect. Thus it really is the scepter about which the psalmist sings: “The Lord sends forth the scepter of Your power out of Zion, by which You will rule in the midst of Your enemies” [Ps. 110:2].
Those are the words of Brenz.