That great defender of the liturgical calendar John Calvin 
also preached ‘on’ Epiphany (January 6, 1551, just days after his famous and often referenced sermon from the same Book of Micah on December 25, 1550/51—the first of the year at that time), because it was a normal weekday preaching.[1]
[1] Calvin, Sermons on the Book of Micah, trans. Farley, 362–364.
[2] “See the Institutes 3.7.7 and 4.13.4. In the latter, Calvin maintains that intentions are important, but God just as often finds them more displeasing than acceptable.”
[3] “Simplicité can mean ‘artlessness,’ ‘plainness,’ and ‘singleness’ as well.”
[4] “In the French text, Calvin refers to this festival as ce jour des Rois—“the day of the King.” However, the Supplementa editors explain that since the Reformers had abolished the ecclesiastical calendar along with its festivals and special days, Sundays excepted, Epiphany (or January 6, the very day of this sermon) was no longer observed.”
[5] [At the Reformation Geneva had a population of about ten thousand, and there were two thousand in the surrounding rural areas under the city's control. Cf. Manetsch, 126, and Brill's Companions to the Christian Tradition, v. 72, Companion to the Swiss Reformation, ed. Amy Nelson Burnett and Emidio Campi (Leiden ; Boston: Brill, 2016), 366.]
also preached ‘on’ Epiphany (January 6, 1551, just days after his famous and often referenced sermon from the same Book of Micah on December 25, 1550/51—the first of the year at that time), because it was a normal weekday preaching.[1]Now, he [Micah] mentions the “statutes, ordinances, and the ceremonies” because idolatry always promotes itself as virtuous activity. For idolaters imagine that they are worshipping God in everything they do, even when their services are foolish, which the blind and the Devil make others believe God approves. We still witness the same occurring today. For those who worship God in accordance with their fantasy, as in the papacy, dishonor and blaspheme God rather than worship God. Yet the papists are so arrogant as to think that God is obligated to accept what they do. And they justify it on the ruse: “Ah, will not God accept whatever is done on the basis of a good intention?”[2] That is how mankind hope to obligate God by their stupid fantasies, while avoiding any adherence whatsoever to his will. Now because this pride also gripped the Jews, Micah responds with equal loftiness: “Yes, of course! You tell me that these statutes, decrees, and ordinances provide wonderful advice and counsel and dictate what you should do. Very well! I will grant you your lofty words, but, nevertheless, God considers all of it an abomination, and, in believing that you are worshipping God by means of your silly fantasies, you are actually confessing that you have been worshipping the Devil.” If we would worship God as we should, then this passage [Micah 6:12-16] forces us to expend the effort to ground ourselves in the pure simplicity[3] that God has set forth in his Word.
That constitutes a doctrine we cannot ignore. For no matter what pretext we might use, or how noble we find our own cause to be, all that is rejected and condemned by a single word, namely, “obedience.” For with good cause, God prefers it above all else, desiring that we worship him in simplicity and obedience. But when we surpass those limits, we corrupt our cause. And although we might impress others, one may still say: “Yes, what a devout man! What a devout woman! but I tell you, they are both bigots!” For irrespective of what they may mumble, or of how many masses they attend; irrespective of how many relics they worship, or votive candles they may light, or how many times they have been saluted as “good people,” it amounts to nothing but a grievous offense against God. Hence, even if we are admired by others, we will not escape God’s condemnation unless we follow what he has commanded in his Word.
Now by this example, we are instructed to adhere to the pure simplicity of God’s Word, even though we are prone to disregard it. True, we might not turn against it at first, but soon after God has been gracious enough to teach us, we are easily corrupted. In fact, the majority are immediately carried away, some in order to follow their accustomed idolatry and superstitions—for whatever bizarre and stupid reason I know not, while others cease to care about God and his Word at all, or they care about as much as animals do, while others, driven by their contempt and disgust for God’s Word, vent their rage on both its teaching and those who preach it. When we observe such an ingratitude on the part of mankind, there arises the danger that we may fall into an abyss far more destructive and horrible than the one from which our Lord retracted us, thanks to his infinite goodness. For although one might daily explain what has been done in order to worship God, the majority will continue to pursue their habitual course and old superstitions. For example, how many people still regard Epiphany with high reverence?[4] They even celebrate the festival as they have been accustomed to do. I know not where they came up with this festival of “the king.”
Now even though people openly know that all this is pure mockery of God, and that the only reason why the papists observe this festival is in order to get drunk, stuff themselves, and behave in the most intemperate and dissolute way, nevertheless, if you were to ask three hundred, or even a thousand Genevan inhabitants,[5] if it were good to celebrate this festival, they would reply: “Why not? What harm can result from honoring God in this way?” That is the response that many would make, even though they are supposed to be instructed in the Word of God and know that such falsehood is nonsense. This is not how we should act. For if we hope to worship God in the manner that is acceptable to him, we must divest ourselves of all silly superstitions and frivolous inventions, renounce all idolatry in order to worship God in spirit and in truth (as God commands us), and cling to the simplicity that we observe in his Word.
[1] Calvin, Sermons on the Book of Micah, trans. Farley, 362–364.
[2] “See the Institutes 3.7.7 and 4.13.4. In the latter, Calvin maintains that intentions are important, but God just as often finds them more displeasing than acceptable.”
[3] “Simplicité can mean ‘artlessness,’ ‘plainness,’ and ‘singleness’ as well.”
[4] “In the French text, Calvin refers to this festival as ce jour des Rois—“the day of the King.” However, the Supplementa editors explain that since the Reformers had abolished the ecclesiastical calendar along with its festivals and special days, Sundays excepted, Epiphany (or January 6, the very day of this sermon) was no longer observed.”
[5] [At the Reformation Geneva had a population of about ten thousand, and there were two thousand in the surrounding rural areas under the city's control. Cf. Manetsch, 126, and Brill's Companions to the Christian Tradition, v. 72, Companion to the Swiss Reformation, ed. Amy Nelson Burnett and Emidio Campi (Leiden ; Boston: Brill, 2016), 366.]
