The following writings of John Calvin are from his commentaries, and (lastly) an excerpt from his book, “The Necessity of Reforming the Church”.
On Jeremiah 7:31
Which I commanded them not, and which never came to my mind: This reason ought to be carefully noticed, for God here cuts off from men every occasion for making evasions, since he condemns by this one phrase, “I have not commanded them,” whatever the Jews devised. There is then no other argument needed to condemn superstitions, than that they are not commanded by God: for when men allow themselves to worship God according to their own fancies, and attend not to his commands, they pervert true religion. And if this principle was adopted by the Papists, all those fictitious modes of worship, in which they absurdly exercise themselves, would fall to the ground. It is indeed a horrible thing for the Papists to seek to discharge their duties towards God by performing their own superstitions. There is an immense number of them, as it is well known, and as it manifestly appears. Were they to admit this principle, that we cannot rightly worship God except by obeying his word, they would be delivered from their deep abyss of error. The Prophet’s words then are very important, when he says, that God had commanded no such thing, and that it never came to his mind; as though he had said, that men assume too much wisdom, when they devise what he never required, nay, what he never knew. It is indeed certain, that there was nothing hid from God, even before it was done: but God here assumes the character of man, as though he had said, that what the Jews devised was unknown to him, as his own law was sufficient.
Now, as the words Tophet and Gehenna were so stigmatized by the prophets, we may hence learn how displeasing to God is every idolatry and profanation of his true and pure worship: for he compares these notorious places in which the Jews performed so sedulously [diligently] their devotions, to the infernal regions. And hence at this day, when the Papists boast of what they call their devotions, we may justly say, that there are as many gates, through which they throw themselves headlong into hell, as there are modes of worship devised by them for the purpose of conciliating God.
On Micah 6:8
It is mere calumny, then, in our enemies to accuse us of alluring men by facilities and indulgence. For were the option given, there is nothing which the carnal man would not prefer to do rather than consent to worship God as prescribed by our doctrine. It is easy to use the words faith and repentance, but the things are most difficult to perform. He, therefore, who makes the worship of God consist in these, by no means loosens the reins of discipline, but compels men to the course which they are most afraid to take. Of this we have most pregnant proof from fact. Men will allow themselves to be astricted by numerous severe laws, to be obliged to numerous laborious observances, to wear a severe and heavy yoke; in short, there is no annoyance to which they will not submit, provided there is no mention of the heart. Hence, it appears, that there is nothing to which the human mind is more averse than to that spiritual truth which is the constant topic of our sermons, and nothing with which it is more engrossed than that splendid glare on which our adversaries so strongly insist. The very Majesty of God extorts this much from us, that we are unable to withdraw entirely from his service. Therefore, as we cannot evade the necessity of worshipping him, our only remaining course is to seek out indirect substitutes that we may not be obliged to come directly into his presence; or rather, by means of external ceremonies, like specious masks, we hide the inward malice of the heart, and, in order that we may not be forced to give it to him, interpose bodily observances, like a wall of partition. It is with the greatest reluctance that the world allows itself to be driven from such subterfuges as these; and hence the outcry against us for having dragged them out into the open light of day, out of their lurking places, where they securely sported with God.
On Numbers 15: 39
For if we scrutinize the intentions of men, it will at length come to this, — that men carefully and anxiously seek various superstitions, because they are unwilling to come before God and to devote themselves to him, without some dissembling and hypocrisy. Since it is so, certain it is, that all who desire to pacify God with their own ceremonies and other trifles cannot by any pretext escape. What is said here is at the same time strictly addressed to the Jews, who had been instructed in the teaching of the Law: and such are the Papists of this day; though they spread forth specious pretenses to excuse their ignorance, they may yet be refuted by this one fact, — that God has prescribed clearly and distinctly enough what he requires: but they wish to be ignorant of this; hence their error is at all times wilful.
On Reforming the Church
In regard to the worship of God, our adversaries next accuse us, because, omitting empty and childish observances, tending only to hypocrisy, we worship God more simply. That we have in no respect detracted from the spiritual worship of God, is attested by fact. Nay, when it had in a great measure gone into desuetude, we have reinstated it in its former rights. Let us now see whether the offense taken at us is just. In regard to doctrine, I maintain that we make common cause with the prophets. For, next to idolatry, there is nothing for which they rebuke the people more sharply than for falsely imagining that the worship of God consisted in external show. For what is the sum of their declarations? That God dwells not, and sets no value on ceremonies considered only in themselves, that he looks to the faith and truth of the heart, and that the only end for which he commanded, and for which he approves them, is, that they may be pure exercises of faith, and prayer, and praise. The writings of all the prophets are full of attestations to this effect. Nor, as I have observed, was there any thing for which they labored more. Now, it cannot, without effrontery, be denied, that when our Reformers appeared, the world was more than ever smitten with this blindness. It was therefore absolutely necessary to urge men with these prophetical rebukes, and draw them off, as by force, from that infatuation, that they might no longer imagine that God was satisfied with naked ceremonies, as children are with shows. There was a like necessity for urging the doctrine of the spiritual worship of God — a doctrine which had almost vanished from the minds of men. That both of these things have been faithfully performed by us in times past, and still are, both our writings and our sermons clearly prove.
In inveighing against ceremonies themselves, and also in abrogating a great part of them, we confess that there is some difference between us and the prophets. They inveighed against their countrymen for confining the worship of God to external ceremonies; but still ceremonies which God himself had instituted; we complain that the same honor is paid to frivolities of man’s devising. They, while condemning superstition, left untouched a multitude of ceremonies which God had enjoined, and which were useful and appropriate to an age of tutelage; our business has been to correct numerous rites which had either crept in through oversight, or been turned to abuse; and which, moreover, by no means accorded with the time. For, if we would not throw every thing into confusion, we must never lose sight of the distinction between the old and the new dispensations, and of the fact that ceremonies, the observance of which was useful under the law, are now not only superfluous, but vicious and absurd. When Christ was absent and not yet manifested, ceremonies, by shadowing him forth, cherished the hope of his advent in the breasts of believers; but now that his glory is present and conspicuous, they only obscure it. And we see what God himself has done. For those ceremonies which He had commanded for a time He has now abrogated forever. Paul explains the reason, — first, that since the body has been manifested in Christ, the types have, of course, been withdrawn; and, secondly, that God is now pleased to instruct his Church after a different manner, (Galatians 4:5; Colossians 2:4, 14, 17). Since, then, God has freed his Church from the bondage which he had imposed upon it, can anything, I ask, be more perverse than for men to introduce a new bondage in place of the old? Since God has prescribed a certain economy, how presumptuous to set up one which is contrary to it, and openly repudiated by Him! But the worst of all is, that though God has so often and so strictly interdicted all modes of worship prescribed by man, the only worship paid to him consisted of human inventions. What ground, then, have our enemies to vociferate that in this matter we have given religion to the winds? First, we have not laid even a finger on anything which Christ does not discountenance as of no value, when he declares that it is vain to worship God with human traditions. The thing might, perhaps, have been more tolerable if the only effect had been that men lost their pains by an unavailing worship; but since as I have observed God in many passages forbids any new worship unsanctioned by his Word; since he declares that he is grievously offended with the presumption which invents such worship, and threatens it with severe punishment, it is clear that the reformation which we have introduced was demanded by a strong necessity.
I am not unaware how difficult it is to persuade the world that God rejects and even abominates every thing relating to his worship that is devised by human reason. The delusion on this head is owing to several causes, — “Every one thinks highly of his own,” as the old proverb expresses it. Hence the offspring of our own brain delights us, and besides, as Paul admits, this fictitious worship often presents some show of wisdom. Then, as it has for the most part an external splendor which pleases the eye, it is more agreeable to our carnal nature, than that which alone God requires and approves, but which is less ostentatious. But there is nothing which so blinds the understandings of men, and misleads them in their judgments in this matter, as hypocrisy. For while it is incumbent on true worshippers to give the heart and mind, men are always desirous to invent a mode of serving God of a totally different description, their object being to perform to him certain bodily observances, and keep the mind to themselves. Moreover, they imagine that when they obtrude upon him external pomp, they have, by this artifice, evaded the necessity of giving themselves. And this is the reason why they submit to innumerable observances which miserably fatigue them without measure and without end, and why they choose to wander in a perpetual labyrinth, rather than worship God simply in spirit and in truth.
By contrasting ‘the hearts and eyes’ of men with His Law, He shows that He would have His people contented with that one rule which He prescribes, without the admixture of any of their own imaginations. And again, He denounces the vanity of whatever men invent for themselves, and however pleasing any human scheme may appear to them, He still repudiates and condemns it…
He says that men ‘follow harlotry’ whenever they are governed by their own counsels. This declaration is deserving of our special observation, for while they have much self-satisfaction who worship God according to their own will, and while they account their zeal to be very good and very right, they do nothing else but pollute themselves by spiritual adultery. For what by the world is considered to be the holiest devotion, God with his own mouth pronounces to be fornication. By the word ‘eyes’ he unquestionably means man’s power of discernment.