“The Church is one, and by her fertility she has extended by degree into many. In the same way, the sun has many rays, but a single light; a tree has many branches but a single trunk resting on a deep root; and many streams flow out from a single source. However many may spread out from the source, it retains its unity. Cut off a ray from the orb of the sun; the unity of light cannot be divided. Break off a branch from the tree, and the broken branch cannot come into bud. Sever the stream from its source, and the severed section will dry up. So it is also with the Church. She is flooded with the light of the Lord, and extends her rays over all the globe. Yet it is the one light which is diffused everywhere, without breaking up the unity of the body. She stretches forth her branches over the whole earth in rich abundance; she spreads widely her flowing streams. Yet there is but one head, one source, one mother, abounding in the increase of her fruitfulness. We are born of her womb, we are nourished by her milk, and we are given life from her breath…Anyone who rends and divides the Church of Christ cannot possess the clothing of Christ.” (Cyprian, “On the Unity of the Church”)
Few of us have given enough sustained, serious reflection to the stupendous reality that Jesus Christ’s final prayer on the last night of his life centered chiefly on his desire for unity among his rag-tag band of disciples, both present and future (John 17:20-23). Regardless, now contrast this poignant scene with the bizarre contradiction that exists in the attitudes of many Western Christians today. Regarding the widespread New Testament call for unity among followers of Jesus, two wildly different sentiments tend to abound in our half-hearted response to the scriptural injunction. On the one hand, the pervasive biblical teaching on unity is generally understood to be both simple in its clarity and direct in its thrust–rightly so, in fact. Christians are expected as a matter of normal practice to exhibit a tangible, lasting harmony with one another on the basis of their shared faith in Jesus’ saving death and resurrection. On the other hand, we often appear quite undisturbed by the massive divisions that exist between various groups of confessing Christians around the world—groups whose authentically Christian status many if not most of us would gladly concede. How these two factors cohere with one another in the modern Christian subconscious is not at all clear, and arguably problematic.
In this new series, I hope to explore the various contours of a fully-fledged Christian unity. In my final posts, I will get around to wrestling with some of the most perennial obstacles to lasting reconciliation between the churches of Christ, and offer up some nitty-gritty practical application for those so interested in being peace makers. Concrete wisdom of the how-to variety remains of keen import in a world as messy, ambiguous, and filled with hues of gray as we find ourselves in. My intention for this series, then, is not speculative in the least. Nothing would thrill me more than to see a marked increase in sincere, intentional, and God-glorifying unity among the various Christian groups here at Harvard, as well as much more heart-felt repentance over our long-standing habits of division and isolation from one another.
The New Testament unambiguously reveals that unity between Christians was of central importance to Jesus and his authoritative, Spirit-filled apostles. For about the first thousand years of church history, there is much evidence to indicate that this passionate commitment continued to be widely shared by those who came after them and very little that expressly contradicts the continuing presence of this conviction. For one particularly pertinent example , consider this excerpt from one of the earliest extant Christian writings outside of the New Testament:
“Why is there strife and angry outbursts and dissensions and schisms and conflict among you? Do we not have one God and one Christ and one Spirit of grace which was poured out upon us? And is there not one calling in Christ? Why do we tear and rip apart the members of Christ, and rebel against our own body, and reach such a level of insanity that we forget that we are members of one another? Remember the words of Jesus our Lord, for he said: ‘Woe to that man! It would have been good for him if he had not been born, than that he should cause one of my elect to sin. It would have been better for him to have been tied to a millstone and cast into the sea, than that he should pervert one of my elect.’ Your schism has perverted many; it has brought many to despair, plunged many into doubt, and caused all of us to sorrow. And yet your rebellion still continues!” (1 Clement 46:5-9, as cited in Michael W. Holmes, Apostolic Fathers: Greek Texts and English Translations, 1999, p. 81)
Many centuries later, the influential Protestant reformer John Calvin echoed a similar commitment:
“Whoever tears asunder the Church of God, disunites himself from Christ, who is the head, and who would have all his members to be united together.” (Commentary on Zechariah 8:23)
While significant theological diversity has always existed in the world-wide church, there was a core of tradition and scriptural teaching that served as the unifying basis of Christian self-understanding (here we think, of course, of the Apostle’s Creed, the Nicene Creed, and the rest of the Seven Ecumenical Councils). Moreover, various individual churches during this primitive era did not as yet identify their primary difference from other collectives of Christians in doctrinal categories, but merely in geographical location. In this they were following a patently New Testament phenomenon, in which the various communities of believers are identified simply by their location in Christ (spiritually) and their geographical location in their respective cities (i.e. in Corinth, Rome, Ephesus, etc.). Their unity was found in the first category, their differences in the second—period. Nothing else set them apart from each other, and nothing else provided a common connection with each other.
While the history behind the “great schism” of 1054 between the Western (Latin) and Eastern (Greek) churches is notoriously complex and detailed, it does serve as the first “official” breakdown of Christian unity in history between two groups that both clearly stood within the apostolic consensus of Nicene and Chalcedon. After another half a millennium in which East and West continued on their separate ways—yet for the most part each remained relatively coherent and organized internally—the Western church suffered another catastrophic split.
With his nailing of 95 theses to the church door in Wittenberg, Martin Luther signaled his theological dissent from the plenteous abuses of the Roman Catholic Church. While this story once more proves to be a radically convoluted one and marvelously resistant to simplistic reductions, it soon came to pass that “Protestants” now joined “Catholics” and “Eastern Orthodox” as the three major groups within “Christendom” in the modern world. Since the time of the Reformation, Protestants have continued to splinter among themselves at an alarmingly exponential rate. Most statistical analyses currently put the number of Protestant denominations in the world somewhere between 20,000 and 30,000, with no signs that the rapid rate of disintegration will soon abate. Unity, it would seem, is distinctly a thing of the past. Worse still, many contemporary Christians fail to exhibit any notable signs of alarm or mourning over this tragic state of affairs:
“Living in divided churches, Christians have become accustomed to division. We easily regard disunity as normal. But easy acceptance of Christian division is, we believe, as great a threat to the integrity of our churches as division itself.” (In One Body Through the Cross: The Princeton Proposal for Christian Unity, p. 18)
In this series of posts I will elaborate upon five crucial aspects of Christian unity, listed in very brief summary form below:
1.) The meaning of Christian unity: this is the state of affairs that obtains when followers of Jesus intentionally live together in mutual acceptance—amidst their considerable ongoing diversity—as reconciled, beloved children of God within a stable community that is supremely devoted to the kingdom of God.
2.) The visibility of Christian unity: the corporate oneness of believers is divinely intended to be visible in the world, and not merely “positional” or “spiritual” or “invisible.”
3.) The priority of Christian unity: this experiential reality is integral to both the identity and the mission of the body of Christ, and cannot be conveniently relegated to the sidelines as a second-order doctrine.
4.) The benefits of Christian unity: when followers of Jesus dwell together in unity, this dynamic inevitably produces a host of valuable spiritual benefits among those who are sacrificially committed to fostering it.
5.) The basis of Christian unity: the common ground that Christians occupy is founded exclusively upon Jesus’ saving death and resurrection. Therefore, this unity among believers arises only derivatively out of the more fundamental event of reconciliation that takes place between God and humanity through the gospel.
Next week: The meaning of Christian unity
Suggestions for Further Reading
Future of the Church (Grand Rapids: Zondervan, 2010)
*Bonhoeffer, Dietrich. Life Together (Harper One, 1978)
*Frame, John. Evangelical Reunion: Denominations and the Body of Christ (Grand Rapids:
*Jenson, Robert (ed.), In One Body Through The Cross: The Princeton Proposal for Christian
Unity (Grand Rapids: Eerdmans, 2003)
*Koivisto, Rex. One Lord, One Faith: A Theology for Cross-Denominational Renewal
*Newbigin, Lesslie. Is Christ Divided? A Plea For Christian Unity in a Revolutionary Age
(Grand Rapids: Eerdmans, 1961)
*Packer, J. I. “Divisions in the Church,” in Shorter Writings of J. I. Packer: Serving the People of
God, Vol. 2 (Paternoster, 2002), pp. 21-30
*Packer, J. I. “The Doctrine and Expression of Christian Unity,” in Shorter Writings of J. I.
Packer: Serving the People of God, Vol. 2 (Paternoster, 2002), pp.31-42
*Warfield, B. B. “True Unity: What It Is,” in Selected Shorter Writings, Vol. 1 (Phillipsburg, NJ:
P & R, 2001), pp. 299-307
 Cf. Psalm 133:1, John 10:16, 11:52, 17:1-26, Acts 1:14, 2:44, 4:32, Romans 15:5-7, I Cor. 1:10, 10:17, 12:12-26, Ephesians 2:14-16, 4:1-16, Philippians 1:27-2:2, 4:2-3, Colossians 3:14-15, etc.
 The standard histories of this period tend to emphasize disagreements over the filioque clause (“and the Son”) and the Pope’s disputed claims to universal validity and authority in Christendom as central to the divide, though all admit that dozens of other factors—not just theological but also historical and social—played important parts in the dissolution of official Christian unity.
 I recognize that I am in danger of giving the impression that events such as the Reformation were only negative and misguided in their divisive effects upon the church of Christ. By no means do I wish to argue this, nor do I believe it. As I will (briefly) elaborate on in future posts, there are times in which believers are called to separate from those who deny the gospel or engage in habitual, unrepentant sin. However, my conviction is that this emphasis has been used, inconsistently so, as an excuse for not taking seriously the strong biblical teaching on unity, and that of late the Western church (in particular) has been lamentably lax in failing to seek restoration in any substantive manner.