On the evening before His crucifixion, Jesus prayed what is known as the Great High Priestly Prayer. It is recorded for us in John 17. In that short chapter, addressing the Father in the presence of His disciples, He prayed four times “that they may be one.” This petition extended not merely to those disciples who were present at the Last Supper, but to “them also which shall believe on me through their word” (v. 20), in other words, to all believing Christians.

Does this mean that there is or should be only one united, visible church? Jesus’ desire for unity among His followers is clear from this prayer, but taken alone it does not answer the question of the nature and structure of that unity. It is often interpreted as meaning that there should be a single church structure, “one holy, catholic, and apostolic church,” as the Nicene Creed puts it, but Jesus does not actually use the word “church,” and it is not evident from the text whether the oneness that He has in mind is organizational, spiritual, or both.

What Jesus wants the Church to be is not altogether clear from the Gospel record, because there are only two occasions on which He uses the word. Both examples are found in Matthew (chapters 16 and 18). The first seems to refer to what we often mean by “the Church” in common parlance, namely, a single institution: Jesus did not say “my churches,” which would emphasize the significance of individual congregations. In the second passage, however, He does use the word to refer to a local congregation.

A great deal of discussion has arisen about the meaning of the term ekklesia; this Greek word did not yet have the specialized meaning “church,” but rather “assembly.” It is used in secular writing in that sense, often referring to a formally constituted body —and a local one. In secular usage, the ekklesia comprises those who are called out, summoned to gather together for official purposes. From the nature of things, an ekklesia in this sense is local. This emphasis on the local nature of the ekklesia is followed by congregationally inclined groups such as the Plymouth Brethren, who think of the church primarily in terms of local assemblies of believers, and in fact they use the word “assembly,” where others would say “church.”

From the dual usage of the word ekklesia in those two passages, it seems that there are two aspects to the question of the unit}’ of the church: Do the words of Jesus mean that there is to be only one unified organization or institution? When Jesus uses the term in Matthew 16:18, He is not referring merely to some local gathering but to something larger, to what we have come to call the Church Universal, hi Matthew 16, Jesus responds to Peter’s declaration of faith, “Thou art the Christ, the Son of the living God,” with the dramatic announcement, “Thou art Peter, and upon this rock I will build my church.” Clearly this is the vision of the Roman Catholic Church, which traditionally looks upon itself as the church meant by the Nicene Creed. Leaving aside the question of whether this means that the Church was to be built on Peter himself and on his successors, as Roman Catholics interpret the text, or rather upon the faith expressed in Peter’s confession, as others see it, it is evident that Jesus is referring to a single structure, i.e., a universal Church.

The second reference, in chapter 18, offers a contrast. It clearly uses “assembly” in a sense that would permit a plurality of assemblies. We hear Jesus telling His followers that when a dispute cannot be resolved after the efforts first of an individual, then of two or three witnesses, “Tell it to the church” (v. 17), clearly referring to a local fellowship.

It is perfectly evident that Jesus desires, even mandates, unity among His followers; what is not evident from the text itself is the nature of this unity, whether it is organizational and visible or spiritual and invisible. In John 17, Jesus repeatedly describes the oneness that He desires for His followers as like that between the Father and Himself; “one as we are” (v. 11). This is unity of a very high degree, but it is obviously a spiritual unity, not an organizational or institutional one. Elsewhere in the New Testament, St. Paul speaks of “the unity of the Spirit,” and frequently refers to the Church as the body of Christ, saying, “one body, and one Spirit, even as we are called in one hope of your calling, one Lord, one faith, one baptism, one God and Father of all, who is above all, and through all, and in you all” (Ephesians 4:3-6). This organic imagery does not negate the concept of institutional unity, but it does not appear to require it. What it does stress is an organic, spiritual, existential oneness. Organizational unity is neither a prerequisite nor a guarantee of spiritual unity. Paul’s terminology does not exclude institutional unity or organizational structure, but it does not seem to require it.

Several European languages have adopted versions of the Greek word, such as eglise (French) and iglesia (Spanish), which can easily suggest a single structure, but do not necessarily do so. The Germanic words church, kirk, and Kirche have drawn upon a different Greek word, kuriakos, which means “belonging to the Lord (Christ).” Neither ekklesia nor kuriakos requires one to think in terms of an organized structure with a unity that is visible to all; both are certainly compatible with the idea of a fellowship that is universal, extending across national boundaries and denominational divisions, but possessing a unity that is spiritual and invisible, not structural and visible.

If one could point to a single Church, such as the Roman Catholic Church, and show that it exhibits true spiritual unity, then the Catholic appeal to “separated brethren” to come “home to Rome” would be more plausible than it is. However, especially since the Second Vatican Council, it has become evident that there is considerable doctrinal, spiritual, and moral disunity within the largest Christian communion, the structural unity and the primacy of the pope notwithstanding. Returning everyone to Rome might merely increase confusion, not establish unity. Evidently, there can be great spiritual unity among traditional believers who belong to different confessions (“historic Christians”) and virtually total disunity among those who belong to the same denomination.

A full outward, structural, visible unity among all of the followers of Christ has never existed. There have been disruptions in the outward unity of the Christian Church from the beginning. The most dramatic was the Great Schism that broke the visible unity between Eastern Orthodoxy and Latin Catholicism in A.D. 1054, but there were earlier breaks among Eastern Christians between the Chalcedonians, the monophysites, and the Nestorians.

The prospect of healing this schism between the Eastern and Western churches was virtually ruined by the Fourth Crusade, which conquered Constantinople instead of Jerusalem, dooming the Roman (Byzantine) Empire to eventual conquest by the Muslim Turks and creating a hostility between the Eastern and Western branches of Christendom that has continued in varying degrees up to the present. What remained of an appearance of unity in the West was demolished by the Protestant Reformation, which produced not only two major branches, Lutheran and Reformed, but also saw the rise of several different interpretations of the faith, some that were orthodox and Bible-centered branches, and others that rejected the Trinity and the deity of Christ. It was not Luther’s goal to found a new church, but rather to bring the one (Western) church back to a truly evangelical faith and practice. Likewise, Calvin and his followers wanted to reform the whole Church, not to establish a separate Reformed Church. The ultimate outcome of the Reformation was the development of a swarm of competing Christian bodies, some of which continued to adhere to biblical standards and credal orthodoxy while others wandered rather far from both. Memories of persecution by Catholics and to some extent by mainline Protestants make many in the Baptist tradition wary of too intimate a contact even today.

Roman Catholics are numerous enough and widely enough spread around the globe to permit them to think of their own organization as the “catholic” church of the Apostles’ and Nicene Creeds, the visible manifestation of the church that Jesus built and the home to which all Christian believers must resort in order to be “one” as Jesus wished. The Eastern Orthodox also tend to think of their own fellowship as the visible church founded by Christ, and in recent years some Orthodox groups have succeeded in breaking out of their traditional ethnocentricity and attracting converts from other backgrounds, including Protestants and Roman Catholics. Yet the prospect of all Christian believers becoming Orthodox seems even less likely than the thought that all might submit to the papacy.

The 20th century has witnessed the establishment of the ecumenical movement, and one of the motives behind the movements that led to the formation of the World Council of Churches in the aftermath of World War II was the goal of bringing Christ to the non-Christian peoples without confusing them with confessional and denominational quarrels. The Roman Catholic Church did not join the World Council, but in the 1960’s the influence of Pope John XXIII and the Second Vatican Council led to a recognition of Protestants as “separated brethren ” who, it was hoped, would eventually return to Rome. However, while trends to collaboration and unification across denominational lines were growing, a retreat from traditional doctrinal convictions and moral standards was taking place not only in mainline Protestantism but also in Catholicism. Indeed, there is more spiritual unity today among conservatives in the different confessions and denominations than exists within individual denominations. Even Roman Catholicism has largely given up its traditional practice of disciplining heretics with excommunication and tolerates the presence of some highly heterodox teachers. Essentially non-Christian trends exist within both the Catholic Church and the Protestant fellowships, so that both groups have numerous adherents who hardly deserve to be called Christians.

In this century, several different groups of Protestant churches have sought a measure of organizational unity: There have been a number of church mergers and there are ongoing discussions between officials and theologians of different denominations seeking organizational unity. Unfortunately, such discussions more often than not seem to result in a sort of lowest common denominator religion, involving the abandonment not only of the distinctive points of doctrine and practice that divided the denominations but also giving up some of the foundational principles of Christian faith and morals.

Consequently, a traditional, believing, or conservative Protestant will probably say that the only unity that can be achieved in the present spiritual climate is a spiritual unity, one that can be perceived by believers in different confessions and denominations. The late Georges Florovosky, a rather evangelical Orthodox priest, used to say, “The Christian is never a stranger where our blessed Lord is loved and worshiped.” This is not merely a unity faute de mieux, because of lack of anything better, but may truly exemplify what Jesus meant when He prayed, “One, even as we are one.”