The Unity of the One Church

“Come on now, how can you, as an evangelical Protestant, speak seriously about the unity of the church? You can hardly agree on anything amongst yourselves!” So guffawed my English Catholic friend whose recent “homecoming” to Rome from Evangelicalism bore all the enthusiasm of a neophyte–along with acute knowledge of the perceived issues and real problems besetting modern-day evangelical Protestantism. At the end of a two-hour debate in an English pub where our topics ranged from personal anecdotes to modestly serious analyses of ecclesiastical history, my friend suggested that I read the seventeenth-century Roman Catholic polemicist, Jacques-Bnigne Bossuet, whose History of the Variations of the Protestant Churches would help to disabuse me of the notion that Protestants could, in good conscience, continue to confess the article in the Nicene Creed that we believe the church to be “one, holy, catholic, and apostolic.”

That was in September of 1998. Since then I have read Bossuet’s History as well as some contemporaneous Protestant counterarguments from David Blondel, a Huguenot church historian. I have also read treatises by two representative Puritans, John Owen and Richard Baxter, as part of my graduate work in church history. As confessing evangelicals, we can and should reflect more biblically and theologically on the nature and necessity of the church’s unity.

When Did the Church Begin?

When we discuss church unity, we must ask two crucial and interrelated questions: First, When did the church begin?, and, secondly, What is true church unity?

The first question requires us to clarify how God has worked out his decree of election in history. The church plays a key role in this. Some Christians, while acknowledging that the church–its nature, identity, and the number of individuals within it–is part of God’s eternal plan of predestination, would however limit the use of the word church to the time after its New Testament beginning at Pentecost (see Acts 2). But other Christians, although they would acknowledge some significant differences between Old Testament Israel and the New Testament church, would interpret these differences as matters of development and not as matters of radical dichotomy or of different dispensations. They would interpret what happened on the day of Pentecost as the New Testament and Christological fulfillment of what was foreshadowed in the Old Testament.

Some sixteenth-century reformational confessions unequivocally assert that the church has always existed. For instance, the Heidelberg Catechism (1563) confesses that the “Holy Catholic Church” was chosen “out of the whole human race, from the beginning to the end of the world.” Zacharias Ursinus, in his commentary on that catechism, states that “there is but one church of all times, from the beginning to the end of the world, there can be no reasonable doubt; for it is manifest that the church has always existed, even before the time of Abraham…. And hence it is also evident that the church, both of the Old and the New Testaments, is one and the same.” Similarly, the Augsburg Confession (1530), the Scottish Confession of Faith (1560), and the Belgic Confession (1561) all assert that the church has existed from the world’s beginning and will last until its end.

In his Confession de Foi Du Chrtien, Theodore Beza (who was Calvin’s successor in Geneva) writes that the church is “a multitude and assembly of such persons whom it has pleased God to choose by His grace.” In this sense, the church has existed, at least embryonically and typologically, from the beginning of human existence. In his lectures on Genesis, Martin Luther states that the historical outworking of God’s plan of election and redemption is through the church. He traces its inception to Genesis 2:17, where God prohibits Adam from eating from the tree of the knowledge of good and evil. After observing that “the church [was thus] established by the Word of God,” he asserts that it was established before the family because “God wants to show by this sign . . . that man was created for an immortal and spiritual life” of fellowship with God. The fellowship that Adam and Eve enjoyed with God as well as the harmony that existed between them were two complementary aspects of true unity, vertically and horizontally considered. With the Fall, this unity was radically ruptured. In commenting on the story of Cain and Abel, Luther writes:

Moreover, here the church begins to be divided into two churches: the one which is the church in name but in reality is nothing but a hypocritical and bloodthirsty church; and the other one, which is without influence, forsaken, and exposed to suffering and the cross, and which before the world and in the sight of that hypocritical church is truly Abel, that is, vanity and nothing. For Christ also calls Abel righteous and makes him the beginning of the church of the godly, which will continue until the end (Matt. 23:35). Similarly, Cain is the beginning of the church of the wicked and of the bloodthirsty until the end of the world.

These words poignantly reflect the fractured ecclesial reality that Luther faced in 1536.

This view of the church as beginning at creation was not Luther’s novel exegetical invention. Luther cites Augustine’s City of God (bk. XV, chap. 7) as supporting his claim about the coexistence of the true and false church. Writing almost 150 years after Luther, John Owen, in his commentary on Hebrews, agrees that Cain and Abel give us “the Prototype of the Believing and Malignant Church in all Ages; of them who under the profession of Religion are born after the Spirit, or after the Promise; and those that are born after the flesh only…. This,” Owen says, “was the first publick visible acting of the Enmity between the seed of the woman, and the seed of the Serpent.”

What Is True Church Unity?

The idea of the church’s unity is tremendously significant for Christian thinking about our life together. In America, rugged individualism has spawned individualistically oriented ecclesiologies that inevitably have bad effects. How can we speak of “one church” when at our local level, we are seldom aware of–or, in fact, are positively apathetic toward–the spiritual well-being and outreach of neighboring churches? As heirs of Augustine’s distinction between the invisible and the visible church, we may retort that true unity is invisible. The one church, the company of God’s elect, the bride of Christ, and the gathering of those indwelt and empowered by the Spirit, is invisible. Thus, we may make a case for our relatively undisturbed conscience when we discern a lack of visible unity. In addition, a hallmark of American Evangelicalism is our tendency to view the church as a voluntary organization–something like a civic club that we choose to join according to our tastes, our preferences, and our affinities. These, however, are unbiblical notions.

Scripture describes the church as God’s people (see Heb. 4:9; 11:25; 1 Pet. 2:10); as Christ’s bride (see Rev. 19:7; 21:9; cf. Isa. 62:5; 2 Cor. 11:2; Eph. 5:25-32); and as his body (see 1 Cor. 12:12-27; Eph. 4:12; 5:23). These metaphors, along with some others (see, for instance, Heb. 3:3-6 for the church as God’s house and 1 Cor. 3:6-9 for the church as God’s crop), show that the church is a divine institution (see also Matt. 16:18; Acts 2:47). The Triune God creates it with his Word and Spirit (see James 1:18; 1 Pet. 1:23; Gal. 3:1-5; Tit. 3:4-7), with Christ as its head (see Eph. 5:23; Col. 1:18; 2:19) and bridegroom, and with his Holy Spirit as its sanctifier (see 1 Cor. 6:11; 2 Thess. 2:13; 1 Pet. 1:2) and the guarantee (see 2 Cor. 1:22; 5:5) that its members will participate in the eschatological wedding supper of the Lamb (see Rev. 19:6-9). So true church unity is grounded in the Triune identity of our God. The mutual indwelling–called perichoresis–within the Persons of the Father, Son, and Holy Spirit, in their genuinely free and loving, other-exalting and self-giving communion forms the basis of our unity, both with God and with one another. Thus, the Trinity provides an infallible model for the church, and the unity exhibited within the church is to be an earthly reflection of the heavenly Tri-unity of God.

This is very clear in Jesus’ high priestly prayer for Christian unity as it is found in John 17:20-23. Based on the true unity of fellowship that exists between the Father and the Son (v. 21), Jesus asked for an analogous fellowship between the church and the Triune God (vv. 21-22). Calvin says that in this prayer Jesus “again places the end of our happiness in unity, and justly. For the ruin of the human race is that, alienated from God, it is also broken and scattered in itself. Conversely, therefore, its restoration lies in its proper coalescence in one body”–that is, Christ’s body, brought into being through his own redeeming work. Jesus came to restore the unity of will and purpose that was lost in the Garden, both vertically–between God and humanity–and horizontally–among human beings. “Wherefore,” Calvin concludes, “whenever Christ speaks of unity, let us remember how foul and horrible is the world’s scattering apart from Him.” And let us learn as well “that the beginning of a blessed life is when we are all governed and live by the one Spirit of Christ.”

This emphasis on Christ’s headship of the church as the source of its true unity was part of the earliest Christian theological reflection. In the post-Apostolic period, the leading idea of the church was clearly grounded in Christ: ubi Christus ibi ecclesia (“where Christ is, there, too, is the church”). First articulated by Ignatius of Antioch (a.d. c. 50 – c. 117), this slogan was extrapolated from Paul’s doctrine that Christ is the church’s head and his conviction that the vitality of the church’s faith and witness was utterly dependent upon recognizing that fact. In this sense, the church’s unity is always, first and foremost, a spiritual reality rather than a sociological fact.

Again, Irenaeus (a.d. c. 130 – c. 200), in his classic treatise against the heretics, speaks of the church’s unity in its faith and witness in these terms:

As I have already observed, the Church, having received this preaching and this faith, although scattered throughout the whole world, yet, as if occupying but one house, carefully preserves it. She also believes these points of doctrine just as if she had but one soul, and one and the same heart, and she proclaims them, and teaches them, and hands them down, with perfect harmony, as if she possessed only one mouth.

He then proceeds to give a remarkable testimony to this unity in faith among far-flung churches: “For the churches which have been planted in Germany have not believed or handed down anything different, nor do those in Spain, nor those in Gaul, nor those in the East, nor those in Egypt, nor those in Lybia, nor those which have been established in the central regions of the world.”

For Irenaeus, the church’s unity is exhibited in the uniformity of its believing and preaching–it consistently believes and proclaims the apostolic kerygma that is at the core of Christian doctrine. This kerygma testifies to the Triune God’s work in redemption, focusing on the Father’s sending of the Son, the Son’s Passion and Ascension, and the coming of the Holy Spirit. In this way, the unity of faith in the confession of the supremacy and sufficiency of Christ’s work and thus the establishment of his headship has always been fundamental to the church’s unity.

This emphasis on Christ’s headship of the church as the source of its unity runs down through the Christian centuries. For example, the Westminster Larger Catechism answers question 64, “What is the invisible church?,” like this: “The invisible church is the whole number of the elect, that have been, are, or shall be gathered into one under Christ the head” (my emphasis).

A Closer Look at the Scriptures

Let us now look more closely at what the Scriptures say about Christ’s church. Regarding our question, “When did the church begin?,” it is helpful to note that the Greek New Testament’s word for the church–that is, ekklesia–appears 69 times in the Septuagint, which is the Greek translation of the Hebrew Old Testament that the writers of the New Testament commonly used. In secular Greek, an ekklesia is an assembly of people–and especially an assembly of people that has been summoned by a herald, just as its etymology suggests. (Ek– is a prefix meaning “out” and kalein is the root for –klesia and means “to call.” For a New Testament example of the word being employed in its secular sense, see the story of the riot in Ephesus in Acts 19:21-41, where ekklesia gets translated “assembly” in vv. 32, 39, and 41.) In the New Testament, with the exception of the passage just mentioned, ekklesia always refers to those who have been called by God to be his people.

In the Septuagint, the word ekklesia translates the Hebrew word qhl. Qhl refers to a congregation or an assembly of God’s Old Testament people–and especially those assemblies where God’s people are gathered before him. For instance, in Deuteronomy 4:10; 9:10; 10:4; and 18:16, the noun ekklesia and its verbal equivalents are used to speak of the assembly of the covenanted Israelite community, an assembly whose identity was that of a people called by God out of the land of Egypt in the Exodus, whose chief patriarch Abraham was himself called by God out of Ur of the Chaldeans (see Gen. 12:1ff). For these Israelites, their primary identity as God’s people was defined by God’s gracious condescension in giving them the Mosaic covenant.

In the New Testament, this notion of the “people of God” becomes the framework for Peter’s understanding of the church as those who have experienced the New Exodus through the redeeming work of the prophet who is greater than Moses, namely, Jesus Christ himself. Thus, Peter declares that the church is “a chosen race, a royal priesthood, a holy nation, a people for [God’s] own possession” (1 Pet. 2:9), which clearly reappropriates the Old Testament metaphors concerning Israel’s privileged covenantal relationship with God. Moreover, in Acts we find Stephen speaking of Moses’ being “in the congregation [ekklesia] in the wilderness” (Acts 7:38).

Thus, in both the Old and New Testaments, God’s people find their true unity with God by his bringing them into a gracious covenantal relationship with himself. Moreover, this vertical redemptive realignment grounds genuine expressions of ecclesial unity “horizontally.” In this context it is also clear that God is bringing to completion in the New Testament era what he began in Old Testament times. So, in Romans 9-11, Paul speaks of the inscrutable and marvelous wisdom of God’s purpose in election when the gentiles, “who were not my people” (Rom. 9:25; cf. Hos. 2:23), now become part of his people by being grafted into his olive tree on account of Israel’s rejection of her Messiah (see Rom. 11:1-24). In the unfolding of God’s redemptive mystery, this gentile “engrafting” clearly demonstrates the nature of God’s progressive revelation whereby through Christ’s work, as the seed of Abraham (see Gal. 3:16), the blessing of unity with God and other human beings can finally be enjoyed. In Ephesians 2:14-16, we again find this idea of the one people of God, with Jews and Gentiles gathered together in Jesus who is both Israel’s Messiah (see John 1:41; 4:19-26) and the world’s Savior (see John 4:42; 1 John 4:14).

Thus, while there are indeed some significant differences between Old Testament Israel and the New Testament church, these differences are primarily matters of development and not matters of radical dichotomy or of different dispensations. What happened on the day of Pentecost is the New Testament and Christological fulfillment of what God had already begun in the Old Testament. And so reformational confessions asserting that the church has always existed are correct.

In considering the biblical evidence for saying that the church, as the people of God, has always existed, we have already begun to unearth some of its evidence for the claim that the church finds its true unity in Christ. One of the chief New Testament metaphors supporting this latter claim involves its references to the “body of Christ” (1 Cor. 12:27; cf. 12:12-27; Eph. 4:12; 5:23). This metaphor speaks of the organic unity that exists between Christ and his church as well as between separate local churches. In this way, it stresses the corporate dimensionality of the church. And so, as I suggested earlier, solitary individualism has utterly no place in Christ’s church, as Calvin emphasizes in his exegesis of 1 Corinthians 12:12. He there draws a very sharp distinction between a civic “body-politic” and the church:

[I]t is quite a common thing for any association or company of men to be called a body, as, for instance, the body-politic, the governing body, and the body of the people. Once, long ago, when Menenius Agrippa wanted to reconcile the Roman people to the senate, against whom they were rebelling, he told a fable, which bore some resemblance to what Paul is teaching here. But the situation is entirely different in the case of the Christians, for they do not constitute a mere body-politic, but are the spiritual and mystical body of Christ, as Paul himself adds.The meaning, therefore, is this: even if there are different members in the body, with different functions, yet they are connected together in such a way as to form a unity. Therefore, we who are members of Christ, even if we are equipped with different gifts, ought nevertheless to be concerned about that union with each together, which we have in Christ.

Can any of us, as we reflect on these words, be cavalier about the well-being of other Christians or about the well-being and outreach of neighboring churches?

Referring to this same passage, C. S. Lewis provides an incisive critique of our tendency to see the church as a voluntary organization–something like a civic club that we choose to join according to our tastes, our preferences, and our affinities–when he says, “[T]he Church is not a human society of people united by their natural affinities but the Body of Christ, in which all members, however different … must share the common life, complementing and helping one another precisely by their differences.”

In Christ’s church, there is not only no place either for rugged individualism or for the indulgence of mere subjective affinities. Instead, we must strive for a true communion with all of God’s saints. Indeed, this is our duty, given our conviction that God the Father is the giver of “every good and perfect gift” (James 1:17), that Christ is our true head, and that we are united through the bond of the Holy Spirit in true brotherly charity.

This body metaphor, with Christ as the body’s head, establishes the sheer necessity of all of us, as members of one body, to coexist and even to become codependent. That is the force of Paul’s epistolary greeting to the factious Corinthians: “Paul, called by the will of God to be an apostle of Christ Jesus, and our brother Sosthenes, to the church of God that is in Corinth, to those sanctified to Christ Jesus, called to be saints together with all those who in every place call upon the name of our Lord Jesus Christ, both their Lord and ours” (1 Cor. 1:1-2).

This greeting then becomes the basis for the following apostolic entreaty: “I appeal to you, brothers, by the name of our Lord Jesus Christ, that all of you agree and that there be no divisions among you, but that you be united in the same mind and the same judgment” (1 Cor. 1:10). In commenting on this verse, Calvin reaffirmed the centrality of the unity of the church for both its witness and its safety: “Let us . . . take note that there is nothing more out of keeping for Christians than their being divided from each other. For the most important principle of our religion is this, that we be in concord among ourselves. Moreover, on this agreement the safety of the Church rests and depends.”

In Ephesians 4:1-16, Paul encourages the Ephesians “to maintain the unity of the Spirit in the bond of peace” by reminding them of the great oneness that already exists in their midst. Reversing the order of Paul’s exposition here, his logic is something like this. There is only one God and Father of all, whose redeeming purposes and power were most clearly demonstrated in the life, death, and resurrection of his Son, Jesus Christ. This Christ is the one Lord in whom Christians put their one faith. There is also only one baptism by which we Christians receive forgiveness and identify with Christ’s death and resurrection. And there is only one Spirit who sanctifies us and calls us to one eschatological hope. In virtue of all of this, we are therefore reminded of the reality of the one body of Christ, of which we all as Christians are members. Elsewhere, Paul makes it very clear that we not only share one baptism but that we also share one loaf in the Lord’s Supper, by which “we, who are many, are one body, for we all partake of the one loaf” (1 Cor. 10:17 [niv]; cf. Rom. 12:5).

One more metaphor that helps us to appreciate the nature of the church’s unity is its description as Christ’s bride. In Ephesians 5:22-33, Paul explores the mysterious analogy between a husband and his wife and Christ and his church. Among other things, this passage emphasizes that Christ nourishes and cherishes the church by infusing his own life and breath into it. This is the inseparable relationship that exists between Christ and his bride. In the Old Testament, other descriptions of the divine-human relationship employ conjugal/covenantal terms as well. For instance, in Isaiah 54:4-10, the Lord (that is, Yahweh, the personal, covenant name for God) speaks of the future glory of Zion by using husband-wife imagery, connoting the depth of his affection and concern for his covenant people. In Jeremiah 2 and Hosea 1-2, Israel’s wholesale betrayal of her God is painfully depicted in terms of marital infidelity. Yet in both books, over and against Israel’s covenantal disobedience, the Lord speaks of redemption, restoration, and rest.

This analogy of the church as Christ’s bride reaches its climax in the breathtaking depiction of the wedding supper of the Lamb in Revelation 19:6-9; 21:1-2, 9-14. In this eschatological reality we see the church’s corporate identity to be that of the bride who “has made herself ready” for the consummation of all of redemptive history in her marriage to the Lamb. She will then appear as a “bride adorned for her husband,” and as the “wife of the Lamb.”

Altogether Lovely

Such a captivating picture can be both invigorating and discouraging at the same time: invigorating because it is the glorious reality that we will some day participate in, but discouraging because the bride seems to wear a tattered and torn dress all too often. However, as John Murray, the late professor of systematic theology at Westminster Theological Seminary, has said, disunity among Christians is not an option: “The mysterious unity of believers with one another must come to visible expression so as to be instrumental in bringing conviction to the world.”

Yet the unity we should so dearly desire must not be procured or preserved at the cost of the purity of the gospel. The church is to be a living testimony to that pure gospel. Today, our postmodern milieu gives indiscriminate primacy to tolerance, elevating it to the level of orthodoxy and regarding any dissent from it with the utmost intolerance. Thus, a counterfeit banner of unity flies high under the aegis of love and the celebration of differences, including radical doctrinal deviations. Confessing evangelicals and their churches must not lose their grip either on doctrinal purity or Christian unity. As Herman N. Ridderbos has emphasized: “questions of the legitimacy and of the unity of the Church will continue to find their answer in the conformity of the Church to its foundation in the history of revelation.” And since “the Church is built on the apostolic testimony of the great deeds of God in Jesus Christ,” the “unity of the Church lies in its apostolicity”–in other words, in the purity of its faith.

Between 1795-1817 Yale University witnessed four major campuswide revivals under the presidency of Dr. Timothy Dwight. He wrote of his love for the purity of the gospel and for the unity of the church in several hymns, one of which includes these poignant lines:

I love Thy church, O God.Her walls before Thee stand,Dear as the apple of Thine eye,And written on Thy hand.For her my tears shall fall,For her my prayers ascend,To her my cares and toils be givenTill toils and cares shall end.

May the Triune God continue to unite our hearts with himself and with one another until the day when faith shall become sight and God’s invisible church becomes gloriously visible in all her bridal splendor.