It can be said that whereas Luther was used by God to enable Christ’s church to break with Rome and begin anew with the gospel restored, it was Calvin whom the Lord used to keep His church, once loosed from Rome, from fragmenting into a thousand pieces. It was Calvin, more than any other, whom the Lord used to reinstitute His church as the church Catholic. No one can read Calvin’s Institutes, and especially his letters, and then deny that Calvin, in spite of all the labors and demands placed upon him by Geneva the cantankerous and uncooperative, yet had his eye and heart on the wellbeing of Christ’s church found across Europe and on the gospel cause wherever it could be found.

He labored and argued and reproved and besought the Protestant congregations, with their leaders, to strive for the unity of the faith and to stand in that unity, a unity that, due to our sinful natures, is so fragile that it requires Christ’s Spirit to grant us forbearing meekness, or it would never survive (cf. Eph. 4:2, 3).

G.M.S. Walker puts it well:

[Calvin’s] outlook was surprisingly modern [i.e., not simply occupied with one’s own immediate community or nation, but looking out across the world—KK]. It has been said that “because of its very origin Calvinism is an ecumenical movement.” Whereas Lutherans and Anglicans drew together into national churches [German and English—KK], the followers of Calvin formed an international alliance, reaching out into many lands from the small city of Geneva, and occupying a central position in their churchmanship. Indeed, it is inaccurate to speak of Calvinism at all because, through his efforts for unity, Calvin secured something greater than a merely personal following. He aimed with considerable success at restoring a Reformed [and yet] catholic church (Readings in Calvin’s Theology, p. 239, D.K. McKim, ed., Baker Books, 1984).

It was not that Calvin anointed himself, like some pope, to serve as the great counselor to pastors and their congregations scattered across Reformation Europe. Rather, it was that his Lord thrust it upon him. The Lord gave him supreme gifts of mind and insights into the Scriptures, and, once editions of the Institutes began to be published across Europe, God’s people and the various reformers themselves recognized what the Lord had given them in this man Calvin. To him, with the multitude of issues that perplexed them, they turned for advice, far more so even than to the increasingly cantankerous Luther. They would not be turned away. How Calvin found time among all his other labors to engage in all the correspondences that came to his door from every part of Europe is a marvel all its own.

In the name of Christ’s church catholic, Calvin found it necessary to engage in a twofold approach. On the one hand, he had to defend the Reformation’s break with Rome as not making its leaders guilty of creating schism in the body of Christ. This, of course, was Rome’s charge. To this Calvin, in his pamphlet The Necessity of Reforming the Church, responded:

The last and principle charge which [Rome] bring[s] against us is, that we have made a schism in the Church… and…that in no case is it lawful to break the unity of the Church. How far they do us injustice, the books of our authors [of the reformers—KK] bear witness….

But judgment must be used to ascertain which is the true Church, and what is the nature of its unity…and…to beware of separating the Church from Christ its Head….

We are as ready to confess as [Rome is] that those who abandon the church, the common mother of the faithful, the “pillar and ground of truth,” revolt from Christ also; but we mean a church which, from incorruptible seed… nourishes [her children] with spiritual food (that seed and food being the word of God), and which, by its ministry, preserves entire the truth which God deposited in its bosom… (pp. 125, 127-8, Protestant Heritage Press, 1995).

Calvin’s point is clear—the reformers were not guilty of schism. If Rome had any vestige left of faithfulness to Christ’s authority and Word, the reformers might properly be charged with schism and creating division in the body of Christ. But Rome had long ago, like the priesthood of Old Testament Israel and the synagogues of the apostles’ day, departed from God’s law and gospel, and so had lost all right to call herself the church of Christ or a manifestation thereof.

But now, having broken with Rome, Calvin had a second weighty concern, namely, to be able to answer to his Lord on behalf of Christ’s beloved bride, the church, that he and his contemporaries had done all in their power to maintain and nurture the unity that Christ’s church is to manifest here on earth even in her institutional form, at least to the extent that she can.

Calvin well understood that that unity is found ultimately in Christ’s one Spirit of spiritual life and shared truth (which is why for Calvin the ancient creeds and common confessions were so important). But he also understood that here on earth the church of Christ in her institutional form (though holy in principle) is imperfect and often at odds and prone to fragment. This he witnessed with his own eyes as the Reformation unfolded itself during his life and then in too many instances the Protestants’ unity in truth unraveled as well. When the separation occurred over fundamental theological doctrines and sacramental practices, that was one thing. But when the division was caused by a lack of forbearance in love, Calvin, for all his strong opinions and convictions on nearly every notable biblical teaching, was grieved.

It was this concern that came to expression in Calvin’s well-known response to Thomas Cranmer’s letter (from England) urging Calvin to throw his considerable weight behind “call[ing] together a godly synod [of Reformed theologians across Europe], for the refutation of error, and for restoring and propagating the truth.”

As Cranmer properly noted,

…nothing tends more effectually to unite the Churches of God…than the pure teaching of the Gospel and the harmony of doctrine (Letters of John Calvin, ft. nt. p. 130, The Banner of Truth Trust, 1980).

Calvin responded (in part),

Your opinion, most distinguished Sir, is indeed just and wise…. No remedy can be devised more suitable than if a general meeting were held of the devout and the prudent, of those properly exercised…in the school of God, and of those who are confessedly at one on the doctrine of holiness…. And then I am aware that English matters are not so all-important in your eyes, but that you, at the same time, regard the interests of the whole world…. This other thing also is to be ranked among the chief evils of our time, viz., that the Churches are so divided, that human fellowship is scarcely now in any repute amongst us…. Thus it is that the members of the Church being severed, the body lies bleeding. So much does this concern me, that, could I be of any service, I would not grudge to cross even ten seas, if need were on account of it…. Now, seeing… Churches, though divided on other questions, might be made to unite, I think it right for me, at whatever cost of toil and trouble, to seek to attain this object… (Letters of John Calvin,, to Cranmer, April, 1552).

What is noteworthy is how the divisions at work in the Reformation churches of Calvin’s day, and that between worthy men, sorely grieved him. “…the Church being severed, the body lies bleeding” is vivid language indeed.

But other leading theologians could not be persuaded to gather for another great synod/conference at that time. Cranmer’s great dream never materialized.

Still, Calvin did all he could to foster this unity between leaders and their congregations.

On the one hand, Calvin emphasized with all the vigor and sharpness he could muster the need of every confessing believer to be a member of a church institute! This is where the marks of Christ’s true church enter in, namely, where the gospel of grace is purely preached, the sacraments properly administered, and discipline exercised. A believer is to look about himself for such a church, and then join and remain joined. As Calvin states in his Institutes,

How perilous, then, nay, how fatal the temptation, when we even entertain a thought of separating ourselves from that assembly in which are beheld the signs and badges which the Lord has deemed sufficient to characterize his Church! (IV. 1.11, Beveridge, Eerdmans Publ.).

In the very next section Calvin says things that may surprise some, but make plain that Calvin was a Churchman, that is, not one given to cater to every believer’s independent notions, as if the Reformed faith sponsors or approves of the ultimate autonomy of self, and all things must line up with one’s personal convictions or he has the right to break fellowship with the church institute yet imperfect here on earth. To this individualistic thinking that lacks the grace of forbearance Calvin states the following:

When we say that the pure ministry of the word and pure celebrations of the sacraments is a fit pledge and earnest, so that we may safely recognize a church in every society in which both exist, our meaning is that we are never to discard it so long as these remain, though it may otherwise teem with numerous faults. Nay, even in the administration of word and sacraments defects may creep in which ought not to alienate us from its communion. For all the heads of true doctrine are not in the same position. Some are so necessary to be known, that all must hold them to be fixed and undoubted as the proper essentials of religion: for instance, that God is one, that Christ is God, and the Son of God, that our salvation depends on the mercy of God, and the like. Others, again, which are the subject of controversy among the churches, do not destroy the unity of the faith… (IV.1.12).

For Calvin, in the interests of preserving communion in the church local and for fostering unity of the church catholic, the perspective that “all heads of doctrine are not in the same position” was key.

What is evident is that Calvin had to struggle with a great issue that has always beset (I almost say ‘has bedeviled’) the New Testament church throughout her existence, namely, the striving for the ideal (the church perfect in understanding and love) over against the reality (her weaknesses and deficiencies displayed due to our mortal weaknesses).

This struggle in Calvin’s pastoral soul is nowhere plainer than in his Institutes, in the last part of the Article we just quoted. As he states,

“The best thing, indeed, is [for believers] to be perfectly agreed, but, seeing there is no man who is not involved in some mist of ignorance, we must either have no church at all, or pardon delusion in those things of which one may be ignorant, without violating the substance of religion and forfeiting salvation (IV.1.12).

But having acknowledged this reality Calvin immediately states “Here, however, I have no wish to patronize even the minutest errors, as if I thought it right to foster them by flattery or connivance…” (IV.1.12). He did not want to leave the impression that he was suggesting that what a church confesses in doctrine and life is of little importance, thus patronizing that vulgar spirit so dominating our age, namely, for the appearance of unity let’s crucify truth—unity at whatever cost.

And yet having stated his full commitment to scriptural truths as he was convinced of them, he goes on to say:

…what I say is, that we are not on account of every minute difference to abandon a church, provided it retain sound and unimpaired that doctrine in which the safety of piety consists, and keep the use of the sacraments instituted by the Lord. Meanwhile, if we strive to reform what is offensive, we act in the discharge of duty (IV.1.12).

Note the phrase, “…provided it [a church] retain sound and unimpaired that doctrine in which the safety of piety consists, and keep the use of the sacraments….” This for Calvin was the heart of it, the touchstone according to which membership in a church should and could be maintained, and also according to which churches in various countries with their own peculiarities should strive to maintain an expression of unity international (or catholic)—the doctrines of grace that promote piety and a proper view of the administration of the sacraments with their significance.

That what we have just asserted is true for Calvin is evident from Calvin’s correspondence.

One of the most troubling issues that confronted Protestantism in Calvin’s day (as it does our own) was that of worship and its purity—what Scripture requires, what Scripture allows, and what smells of Rome. Where Calvin stood on the issue of the proper elements of worship was one thing; what he pleaded with Reformed leaders to tolerate to some extent for the sake of unity was another.

There is the well-known history involving the Englishman John Hooper, one that highlights the controversy between the hierarchy of the Anglican church and the non-conformists in their midst. Hooper, when appointed Bishop, refused to wear the required vestments and take the oath prescribed for his installation, leading to his imprisonment. Hearing the news, Calvin wrote Bullinger,

I had rather he [Hooper] had not carried his opposition so far with respect to the cap and linen vestment, even although I do not approve of these (Collected Letters, March 24, 1551).

When the issue of the manner of worship threatened to scatter a congregation composed of French and English refugees in Frankfort, Germany, Calvin wrote to both parties, pleading with them not to march off in their separate ways, banners of accusations flying. What is significant is that Calvin reserved his strongest language for the party with which from a biblical perspective he was most in agreement on this issue, namely, the English party. Hearing of the mounting contention, he wrote the English faction:

This indeed grievously afflicts me and is highly absurd, that discord is springing up among brethren who are for the same faith exiles and fugitives from their country; and for a cause indeed which in your dispersion should like a sacred bond have held you closely united…. Now, on the contrary, that some of you should be stirring up contentions about forms of prayer and ceremonies, as if you were at ease and in a season of tranquility, and thus throwing an obstacle in the way of your coalescing in one body of worshippers, this is really too unreasonable… (C.L. Jan. 15, 1555).

If one cannot hear Calvin’s plea for some forbearance with regard to certain differences that would throw up obstacles to any expression of unity between two believing groups, based on the deeper things of the gospel of grace, one is not listening.

And yet, Calvin sought to be evenhanded as well. Later, in the same letter, he writes,

For my part, if I would not have you to be unduly rigorous towards those whose weakness cannot scale the highest steps of the ladder, [and yet] I would have the others admonished not to have too much complacency in their own ignorance… (C.L. Jan. 15, 1555).

What Calvin is saying is that forbearance between members of that which is undeniably the church of Christ goes a long way, and yet let neither party imagine that it does not have room to learn.

Writing a following letter to his beloved (and sometimes exasperating) younger colleague John Knox, who was one of the leaders amongst the English refugees in Frankfort, Calvin had this to say:

And as I exhorted those who differed from you [in this instance, on the issue of pure worship] to give way a little with what moderation they could, so I own it displeased me, that in your turn you neither gave up nor conceded anything of your opinions (C.L. Jan. 15, 1555, p. 174).

Calvin, as a spiritual father in Reformation Europe, like Paul the apostle in the early New Testament era, pleaded that all do everything within their powers to promote the unity of Christ’s body in its institutional form, not only in congregational life, but in the church universal as well. No, not at the expense of truth, and yet in some matters deferring to others.

As Calvin adroitly summarized it in his letter to Cardinal Sadoleto:

The Church…is the society of all the saints…spread over the whole world, and existing in all ages, yet bound together by one doctrine, and the one Spirit of Christ, [she] cultivates and observes unity of faith and brotherly concord (Reply to Sadoleto,, Tracts I, 37).

Calvin, a churchman of strong convictions, was one who sincerely strove to labor on behalf of his Lord and His beloved bride with this in mind.

Also in the area of the organic unity of the church universal, Calvin is a worthy mentor.