When it came to the New Covenant, John Calvin contradicted Martin Luther on the fundamentals. They cannot both be right. Quotations from both men are set out below, so readers can see and judge for themselves.
When Martin Luther taught about the New Covenant, he extolled its newness and uniqueness. In the quotation below, he referred to it as a “testament,” emphasizing its likeness to a last will and testament. A last will and testament is a document by which a man gives his possessions freely to his heirs (Gal. 3), and which is made irrevocable by the testator’s death. Luther also taught that the Old Testament was a temporary covenant, and that it is now “disannulled” – that is, cancelled, abolished, obsolete. I emphasize these points so that when we get to Calvin, the difference will be clear.
The New Covenant, Luther explained, is Christ’s own promise to us:
Luther: [Christ] made a promise or solemn vow, which we are to believe and thereby come to righteousness and salvation. This promise is the words just cited, where Christ says, “This is the cup of the New Testament.” These we shall now examine.
Not every vow is called a testament, but only a last irrevocable will of one who is about to die, whereby he bequeaths his goods, allotted and assigned to be distributed to whom he will…. And so that little word ‘testament’ is a short summary of all God’s wonders and grace, fulfilled in Christ.
Christ also distinguishes this testament from others and says that it is a new and everlasting testament, in his own blood, for the forgiveness of sins; whereby he disannuls the Old Testament. For the little word ‘new’ makes the testament of Moses obsolete and worthless, one that is no longer in effect. The Old Testament was a promise made through Moses to the people of Israel … a temporal testament …
But Christ, the true paschal lamb (1Co. 5:7), is an eternal divine Person, who dies to ratify the New Testament. Therefore the testament and the possessions therein bequeathed are eternal and abiding. And that is what he means when he contrasts this testament with the other. “A new testament,” he says, so that the other may become obsolete (Heb. 8:13) and no longer be in effect.
William Tyndale agreed with Luther. He taught:
Tyndale: The New Testament is as much as to say a new covenant. The Old Testament is an old temporal covenant made between God and the carnal children of Abraham, Isaac, and Jacob, otherwise called Israel, upon the deeds and the observing of a temporal law. Where the reward of the keeping is temporal life and prosperity in the land of Canaan, and the breaking is rewarded with temporal death and punishment. But the New Testament is an everlasting covenant made unto the children of God through faith in Christ, upon the deservings of Christ. Where eternal life is promised to all that believe, and death to all that are unbelieving.
But against Luther and Tyndale, John Calvin taught that the Old (Mosaic) Covenant was not temporary, not abolished, not obsolete. He also, as will be seen, taught that the New Covenant was not really or substantially new. He said the covenant God made with Abraham precluded anything new, and that the Abrahamic covenant was the real enduring covenant. What need was there then for the covenant that Jesus came to inaugurate? In fact, said Calvin, the Lord came merely to confirm the Abrahamic covenant. Calvin taught that both the Old and New Covenants were merely confirmations of the Abrahamic covenant, and the only difference between them was as to the form and way of teaching.
Below are Calvin’s own words:
Calvin: Now, as to the new covenant, it is not so called because it is contrary to the first covenant, for God is never inconsistent with himself, nor is he unlike himself. He then who once made a covenant with his chosen people had not changed his purpose, as though he had forgotten his faithfulness. It then follows, that the first covenant was inviolable; besides, he had already made his covenant with Abraham, and the Law was a confirmation of that covenant. As then the Law depended on that covenant which God made with his servant Abraham, it follows that God could never have made a new, that is, a contrary or a different covenant…. God has never made any other covenant than that which he made formerly with Abraham, and at length confirmed by the hand of Moses. This subject might be more fully handled; but it is enough briefly to shew, that the covenant which God made at first is perpetual.
Let us now see why he promises to the people a new covenant. It being new, no doubt refers to what they call the form; and the form, or manner, regards not words only, but first Christ, then the grace of the Holy Spirit, and the whole external way of teaching. But the substance remains the same. By substance I understand the doctrine; for God in the Gospel brings forward nothing but what the Law contains. We hence see that God has so spoken from the beginning, that he has not changed, no not a syllable, with regard to the substance of the doctrine. For he has included in the Law the rule of a perfect life, and has also shown what is the way of salvation, and by types and figures led the people to Christ, so that the remission of sin is there clearly made manifest, and whatever is necessary to be known. (Emphasis added)
So Calvin said the Old (Mosaic) Covenant was not really a new thing in its time, and likewise the New Covenant was not really new. Both were just new-ish ways of confirming the Abrahamic covenant, to which God would always be faithful. Christ was a different “external way of teaching” doctrine to the Jews, as well as to the Gentiles who would also be brought into the Church. On this new foundation, Calvin developed his gospel. A few points to note about his teaching:
(1) Calvin emphasized “God’s covenant with Abraham.” The covenant that Luther emphasized was the one given by Jesus. Calvin’s different treatment undermines the primacy of the New Covenant and the agency of Christ.
(2) Calvin said Christ ratified the Abrahamic covenant, not his own, a re-emphasis which also deflects from Christ’s covenant.
(3) Calvin reinterpreted both the means and purpose of this ratification. When Luther used the word ‘ratify,’ he meant chiefly that Jesus died in order to make his covenant irrevocable and eternal. When Calvin used it, he meant that Jesus appeared in order to ratify doctrine and be a new external way of teaching.
In conclusion, Calvin made the Abrahamic covenant to be an overarching covenant that later covenants only confirmed. This meant that the New Covenant could scarcely be so called, because Christ came not to do a new thing, but to manifest or confirm the old. Thus Calvin taught a different covenant. Further, his new doctrine informed all the notes and commentaries, and even several Scripture revisions, in the Geneva Bible. His doctrine is the basis of so-called “Covenantal Theology.” It has a ring of truth, but when it comes down to it, it cannot be harmonized with Reformation doctrine. Part 2 of The Story of the Matthew Bible looks at some of the issues more closely.
In the meantime, I have written a slightly longer (5 ½ pages) paper comparing the Matthew Bible, which agrees with Luther, and the Geneva Bible, which reflected Calvin’s doctrine, which is posted here on Academia.edu.
 Martin Luther, “Treatise on New Testament,” Luther’s Works, Vol. 35, 84-85.
 “WT to Reader,” Tyndale’s 1534 New Testament, 8-9.
 John Calvin, Commentary on Jeremiah 31 at biblehub.com. Accessed during February 2019.