Martin Luther (On John 15:16):
Now let the monks and the whole world go ahead and boast of their merits, and let them choose as long as they please. You hear Christ say: “You did not choose Me, but I chose you.” He refuses to grant that He was chosen by you. All Scripture reproves and condemns any choosing on our part before and without God’s commandment. That is what the Jews did when they instituted their service of God, which they themselves chose and set apart from those ordained and established by God. They captioned it as follows: “This is the chosen service of God. Here we want to find God, reconcile Him, and obtain mercy.” That is how they treated God in everything; they always wanted to take the initiative and to decide upon what should please God. They instituted the use of incense and sacrifice in every vale and on the mountaintops, where there was a green forest or some other attractive spot; and then they boasted that there they had found the true God, who would now have to be gracious to them. Oh, how the prophets wearied themselves rebuking the people because of this abominable vice! Thus we hear Isaiah lament in chapter 66, verse 3: “These have chosen their own ways, and their soul delights in their abominations”; and in chapter 1, verse 29, we read: “For you shall be ashamed of the oaks in which you delighted, and you shall blush for the gardens which you have chosen”; and in chapter 66, verse 3, Isaiah says that he who engages in such self-chosen sacrifices and service of God reminds him of one “who offers swine’s blood; who slaughters an ox is like him who kills a man; he who sacrifices a lamb, like him who breaks a dog’s neck.” Before God such self-chosen holiness is nothing but sheer murder or blasphemy or a denial of God; for in no circumstances will God consent to it if we presume to prescribe and choose what should please Him. We monks used to choose the things that should procure God’s mercy for us. I thought: “Oh, if I enter a cloister and serve God in cowl and tonsure, He will reward and welcome me!”
Thus the entire papacy is nothing but disobedience to and enmity against God. For they are so mad and so stupid that they simply refuse to let God take the first step of seeking and electing them through His word and offering them all His mercy and His friendship through His Son’s suffering and death. All this they disdain and reject. They want to have the glory and the prerogative that God should exist by our grace and do according to our choosing.
Well, this has been the bone of contention in the world ever since the beginning, and I suppose it will remain that until the end. Cain also wanted God to conform to his pattern; he wanted God to have regard for his own work and offering and not for his brother’s. And the world has consistently followed in his footsteps up to the present hour. This is inevitable, for it cannot refrain from reversing the words of our text and saying in fact: “I do not want to be chosen by God, but I want to anticipate Him and choose Him.” But God can and will never tolerate this; He reverses the order and declares: “You cannot and shall not choose Me, but I must choose you. Things will not go as you plan, but as I will. I will be your Lord and Master; I refuse to be taught by you.”
Throughout Scripture, therefore, God condemned and rejected all such choosing without and contrary to His commandment. St. Paul, too, is a bitter enemy of this vice. In Col. 2:18 he says: “Let no one disqualify you, insisting on self-abasement”; also verse 23: “These have indeed an appearance of wisdom in promoting rigor of devotion and self-abasement.” Thus he described the monasticism that was to come; it would introduce nothing but the self-chosen service of God, which it would embellish and adorn by saying: “I mean well, and I am doing this out of love for God and in His honor. Therefore this will please Him, and He will be gracious to me.” Of course, God is twice as hostile to such men as He is to the others; for He Himself tells us how He wants to be served, just as He Himself called the people of Israel out of Egypt and gave them the Ten Commandments, which told them what to do and what not to do, lest they themselves devise and specify how they should serve Him.
Therefore Christ says here: “Just forget about all your boasting that you chose Me. Follow Me, and let Me choose you first. Listen to what I say to you, in order that I, not you, may have the glory of having merited this for you by My blood and death.” Thus He told them to be humble, as Christians must be, because they enjoy the high honor and the great glory of being called Christ’s and God’s friends. God wants them to know and never to forget what made them friends. They must always confess that they have not merited or earned this friendship, but that it has been given to them out of the Lord Christ’s pure grace. A friend who takes and demands nothing of us but only gives and presents everything to us deserves to be loved, cherished, and honored. In other instances, the world accepts favors gladly, but is reluctant to do them. Why, then, is this favor not welcomed? Here on earth we are ready to accept favors from everyone; here no one can do too much for us. But because God wants to give us everything good from heaven, we decline to accept it. Here we want to reverse the order and to do the poor Man, our Lord God, a favor � the One from whom we should accept favors. Here people erect buildings, endow and sacrifice abundantly, give and do what should be given and done, just in order that we may praise the service we are rendering to God. On the other hand, when we are asked to give to our neighbor who is in need of our help, and to do good to him, we will not and cannot do or give anything. In brief, we refuse to accept anything from God, and we refuse to give others anything. This is a shameful and accursed plague inflicted on the human race by the devil, who corrupts and contaminates all that is good, true, and holy.
In some ways, Luther comes very close to the regulative principle of worship here, referencing some of the same texts that would be used in subsequent discussions (the example of Cain, Colossians 2). Obviously he doesn’t quite get that far, perhaps because he is thinking so exclusively in terms of the favor of God, whether we receive it freely or acquire it by effort, that he doesn’t stop to apply his own words to the regulation of worship apart from the question of justification.