JOHN 14:14b (LUTHER)

14b That the Father may be glorified in the Son.

This is surely a strange Man! To reason or the wisdom of the world His speech sounds like that of a dreamer or a drunk. But I did not formulate these words, nor did any other man on earth. And if we were ever so smart, if we and all the sages studied this all our life, we would never hit upon this statement. Therefore even if these words sound foolish in the ears of the clever and the wise, let us be fools with Christ. For those who know and have experienced their power will certainly not regard them as foolishness. God be praised, I, too, have experienced in part what they can do and give; for they have often comforted and upheld me. They still uphold me.
In the preceding words we heard Christ claim the power and honor that belong to God alone. He said that He Himself would grant and do all that the disciples ask. What, then, is the meaning of the words “that the Father may be glorified in the Son”? Why does He now transfer the honor from Himself to the Father? Should He not, according to the natural logic of speech, say: “Whatever you ask, I will do, that I may be glorified”? Who is more entitled to glory than he who performs a deed or a work? It is but natural and proper that he who does something be honored. But now Christ says: “I will do the work and give you what you ask, but My Father shall have the glory.” He rearranges and changes the words in such a way that He includes and embraces both the Father and Himself. For just as He did not exclude the Father with the preceding words, “Whatever you ask … I will do it,” so when He says “that the Father may be glorified,” He does not separate and exclude Himself from the same honor that is due the Father.
But Christ speaks this way in order to substantiate this article, which states that He is true God together with the Father in one Divine Essence yet distinct in Person. He sets Himself apart from the Father, and then He again joins the two; He testifies that the Father is one Person in the Divine Essence and that He is another Person, but that they are still one eternal God, coequal in function and in honor. In German this simply means: “Whatever I do, the Father does; and the Father’s glory is My glory.” Thus He joins the two Persons, His and the Father’s, by rearranging the words “I will do what you ask, that the Father may be glorified in the Son.” For when He says: “I will do it,” He indicates that He is also rightly entitled to the glory; and yet in the words that follow He is silent about His glory and gives this glory to the Father. But if the glory is to be the Father’s, it follows that He must do the very same work that Christ does. On the other hand, if the Father is to have the glory, Christ, who does the same work, must also have the same honor that the Father has.
This is powerful proof that in the Divine Essence there are two distinct Persons but not two natures or two kinds of nature. No, there is just one Divine Essence and Majesty. To summarize: “The work which I do is the Father’s work, so that the Father is glorified in the Son for doing this. Consequently, there is only one glory: He who honors the Son for the sake of the works which He performs honors not only the Son but in Him also the Father.”
What does it mean that the Father is to be glorified in the Son? Nothing else than this, that the Father is to be known and acknowledged as a merciful and compassionate Father, who is not angry with us and does not want to condemn us to hell but remits our sin and grants us all His grace for His Son’s sake, as has been adequately said before. This is the true honor with which God is glorified. For this generates genuine confidence in the heart, which now has refuge in Him, can confidently call upon Him in every need, thanks Him for His grace and benefits, and confesses and proclaims His name before everyone. This is the true service of God that pleases Him and with which He is glorified. But as Christ says, it can be done only “in the Son,” that is, where Christ is known and believed. As has been said, we learn to see God in Him, recognize His grace and fatherly heart, and know that whatever we ask of God in Christ’s name will surely be granted to and received by us.
Luther, M. (1999, c1961). Vol. 24: Luther's works, vol. 24 : Sermons on the Gospel of St. John: Chapters 14-16 (J. J. Pelikan, H. C. Oswald & H. T. Lehmann, Ed.). Luther's Works (24:99). Saint Louis: Concordia Publishing House.