As a Roman Catholic theologian studying ecumenism, I’m sometimes asked by friends, students, and even strangers on planes the question, “So what is that?” I explain that ecumenism refers to the practical, spiritual, and theological attempts to regain the unity of the Christian church throughout the oikumene, that is, throughout the whole world. It’s a relatively easy question to answer. But the usual follow-up question is more difficult, and more challenging, for me and for those who consider themselves professional ecumenists: “Who cares?”

Now, as a graduate student, I’m used to being interested in many things that the average person neither cares nor ought to care about; it goes with the territory of academic study. But lack of interest in the unity of the church is more significant than a simple disregard for theoretical or historical minutiae. Our current lack of interest in matters ecumenical betrays a fundamental assumption: that the unity of the church, the real communion of Christians with each other in bonds of prayer, fellowship, shared institutions and shared worship, is an optional feature of the church, a desirable but not essential add-on to the life of the Christian community – in classical terms, something that is part of the bene esse of the church, rather than its esse, its “well-being”, and not its essential being. I would like to argue from my own Roman Catholic Christian perspective that our common conversion to greater oneness in Christ is a crucial part of our collective discipleship, not because it would “be nice”, nor only because it pragmatically would be of assistance in the mission of the church, but because responding to Christ’s prayer that we might be one as he and the Father are one (John 17:21) is, or ought to be, a central aspect of our life in Christ. The first essential is a theological argument for the centrality of ecclesial unity to the Gospel, and then, by surveying quite briefly some of the history of the ecumenical movement, I will suggest where we have been, where we are now, and where the Holy Spirit is leading us.


Communion and Salvation

Being in communion of faith, life, and witness with other people is not a secondary or accidental aspect of our relation with God in Christ, but an essential part of that relationship – there is no part of our life with God in which we are not simultaneously living that life with others. One can find the starting point for this understanding in Jesus’ statement that the greatest commandment (singular) is to “love the Lord your God with all your heart, with all your soul, with all your mind and with all your strength” and to “love your neighbor as yourself” (Cf. Mark 12:29-31 and parallels). This connection between faith and ethics, between communion with God and communion with humanity, goes deep down within the Christian church’s history, and has been developed and nuanced in numerous ways. The theology I’m going to outline here is based on the work of an ecumenist, theologian, and priest named Jean-Marie Tillard.1

A starting point for understanding how the restoration of our relationship with God entails the restoration of our relationship with each other is the Genesis story of humanity’s creation and our fall into sinfulness. Whether we look at the first creation story’s description of humanity created as “male and female,” as a “them,” or at the more fanciful story of Eve’s creation to be a companion to Adam, Genesis points to the fundamental theological insight that the human being is a homo socialis, a being created in relation to God and to others. And, in the following chapters, we see what happens when the relationship with God is broken in humanity’s disobedience: blame and recrimination shatter the original community between Adam and Eve, and the further effects of the disruption lead to brother killing brother, culminating in the confusion and enmity of Babel. In these very rich texts, at least one major motif is that relationship with God and relationship with others are immutably linked. Part of what it means to be human is that one’s relations with others are causally related to one’s relations with God. The story of God’s covenant with Israel is therefore a love story about the restoration of both.

And so when we as Christians look to Christ, to his life, teaching, death, and resurrection, we should expect that restoration of humanity’s relationship with God in Christ to have a dramatic effect upon our relationships with others. One can see this in the radical table fellowship of Jesus in the Gospels, in his eating with sinners and tax collectors, in his conversations with a Samaritan woman, a Syro-Phoenician woman, and a Roman centurion. After Christ’s death and resurrection, the church very quickly saw itself as fulfilling Isaiah’s prophecy that all nations would come streaming toward Zion; Pentecost reverses Babel by bringing the diversity of nations together in Christ, speaking all languages; and the Letter to the Ephesians sees in the reconciliation of Jews and Gentiles in Christ the prototype of the reconciliation of humanity with itself: “But now in Christ Jesus, you that used to be so far off have been brought close, by the blood of Christ.” (Eph 2:13) And again, in 1 Peter, “Once you were a non-people, and now you are the People of God.” (2:10) Examples in the Scripture, in the practices and liturgy of the early church, and in the writings of the first seven centuries of the church could be multiplied to fill the remainder of this essay. Communion with God and communion with others are intimately related, and there is an ordering, a causality: reconciliation with God causes reconciliation with others, not the reverse. We should be on guard against tendencies toward the absorption of the personal in the collective here; we all, but sometimes especially my own Roman Catholic tradition, can benefit from Martin Luther’s emphasis that salvation is always pro me in addition to being pro nobis.

But without exhausting our understanding of salvation, the Scriptures and the church’s tradition strongly support the idea that an essential aspect of salvation is the reconciliation of human beings with each other that results from our reconciliation with God in Christ Jesus. You cannot have one without the other, and, in this understanding, as personal as your relation to Christ is, it is never an exclusive relationship. The corresponding relation to others, to the community of those who are also in Christ, goes all the way down to the roots. The church, the reconciled community of those who were once enemies, of those who were once a “non-people,” can be the concrete way the Reign of God breaks into our lives, into our experience.


Ecclesial Division: The Great Countersign

Numerous events of the history of the church and of our own experiences call this ideal vision into question; we often fail to be the reconciled and reconciling community that we’re called to be. Here in Boston, the moral failings of our Roman Catholic communities in response to clerical sexual abuse ring in our ears as a great stumbling block for many to see the church as a community of salvation, as a gathering of those being brought closer to God. We know the familiar counter-litanies of Christian believers’ failures in the Crusades, in the pogroms, in wars throughout the centuries, in the conquests of Spain and of the Americas. Even taking into account the historical complexities of all these events, it’s hard not to look at them and be reminded that the church is a community simul justus et peccator, to use Lutheran language; a “pilgrim people,” to use the language of the Roman Catholic Second Vatican Council.

And yet despite the gravity of these historical failures to live up to our collective calling, one of the most significant, longstanding, and spiritually deadening ecclesial realities is the continuing division of those who claim the name Christian. From the earliest divisions of the fifth century up through modern times, the division of the community whose communion is supposed to be the sign and instrument of communion with God is the great countersign to our claim to find salvation in Jesus Christ. The move from “See how these Christians love each other” to “See how these Christians fight each other” has been a recurring obstacle in our response to Christ.

The earliest foundations of the modern ecumenical movement can be found in the missionary congresses of the late nineteenth and early twentieth centuries; missionaries from (mostly mainline Protestant) churches had found their attempts to preach the Gospel to all nations hampered by their own lack of cooperation and by their mutual condemnation. The people to whom they preached pointed to the inherent contradiction of Christian division: how, they asked, are we to believe that in your church God is reconciling humanity to God and to itself, if you aren’t even reconciled with yourselves? The concrete stumbling block of competing, sometimes hostile, missionary societies undermined the message being preached. This and other pragmatic concerns, such as the ability to organize relief work and other financial assistance more effectively, and the ability to collaborate on political and social issues with a unified Christian voice, continue to motivate much ecumenical endeavor today.

But the theology of the church as the place in which humanity is reconciled to God and to itself points to the deeper motivation for ecumenical striving to realize the unity of the church: unity is not primarily to be desired for its effectiveness, it is to be desired because it is what God intends for God’s People. To be one as Christ and the Father are one: that is a major axis of the reality we call salvation, and the starting point for all true ecumenical endeavors is to realize that unity is a good because it is given by God, not because it is more helpful to our projects. And, as given by God, unity is, at its core, a grace, a gift, and not an accomplishment. All of our efforts to restore that unity have the quality of discipleship, of faithful service dependent upon God’s grace. But rather than being an addendum or an appendix to our Christian life, the call to Christian unity is at the very core of the working out of our salvation.


Three Models of Ecumenism

Concretely, what does ecumenism look like? It might help here to look at three models of ecumenical relation
to other Christian churches that show where we’ve been, where we are now, and where we might be going. The examples I’m taking will be from my own Roman Catholic Christian tradition – not because we’ve been better or worse at ecumenism, but because that’s the tradition I know best. (It’s also good ecumenical manners to take negative examples from your own tradition, rather than comparing the best practices of your own church with the worst practices of another.)

The first model can be called the “Come Home to Momma” model; it was the dominant model of relations between different churches for most of the history of Christian division. This extended quotation from Pope Pius XI’s 1928 encyclical Mortalium Animos, his response to the beginnings of the ecumenical movement among Protestant Christians (whom he refers to as “pan-Christians”), gives a good example of what this model entails:

Is it not right, it is often repeated, indeed, even consonant with duty, that all who invoke the name of Christ should abstain from mutual reproaches and at long last be united in mutual charity? […] These things and others that class of men who are known as pan-Christians continually repeat and amplify; and these men, so far from being quite few and scattered, have increased to the dimensions of an entire class, and have grouped themselves into widely spread societies, most of which are directed by non-Catholics, although they are imbued with varying doctrines concerning the things of faith. This undertaking is so actively promoted […] it even takes possession of the minds of very many Catholics and allures them with the hope of bringing about such a union as would be agreeable to the desires of Holy Mother Church, who has indeed nothing more at heart than to recall her erring
sons and to lead them back to her bosom. But in reality beneath these enticing words and blandishments lies hid a most grave error, by which the foundations of the Catholic faith are completely destroyed. (§4)

[T]he union of Christians can only be promoted by promoting the return to the one true Church of Christ of those who are separated from it, for in the past they have unhappily left it. (§10)

Comparable examples from the teachings and practice of other Christian churches could easily be found. At the heart of the model is an assumption that ecclesial division results from the unqualified error of the separated churches in relation to one’s own community; the only way forward to ecclesial unity is for the “erring sons [and daughters]” to come home to Mother Church. If we imagine the life of the Christian church as a highway, starting with the apostles and heading toward the final Reign of God, this model looks at each division of the church as an exit ramp heading off into a dead end; the only option for Christians who have left the main highway is to stop, put the car in reverse, and get back to the one true Church of Christ.

Now, we should not underestimate the fact that there’s an important insight at the heart of this model: Christian communion is not simply a matter of good intentions, but of shared relationship in one faith. The desire to avoid interpretations of the Christian faith that would undermine its truth is important, and it would be a false ecumenism that dismissed any doctrinal differences as irrelevant to Christian unity. Some ecclesial divisions have divided the body of the church from real, and dangerous, “dead ends,” e.g. forms of Gnosticism that attempted to separate the Christian faith from its Jewish origins, or Arianism’s claims that Christ was not fully divine.

But ecclesial divisions are almost never that simple, and often are complex events influenced by numerous political, historical, cultural, and sociological factors – and by the continuing influence of human sinfulness upon the church. An honest assessment of the history of Christian division notes how the goal of maintaining the Christian church in its faithfulness to Christ is often complicated by misunderstanding, by struggles of power between ecclesial leaders, and by gaps of knowledge between different parts of the church. The “come home to momma” model of ecumenical relations fails to address the culpability of one’s own community in the divisions of the church. Furthermore, the divisions of the church were not frozen in time, and the new insights into the faith that were at the roots of the schism were developed, nuanced, and brought to fruition in the lives of other communities. These new insights are gifts for the other churches. For example, my own Roman Catholic community would not be the church it is today without our Protestant sister churches’ emphasis upon the primacy of Scripture. Similarly, the liturgical movement in the twentieth century that revitalized the Mass within my church also assisted Protestant churches in reclaiming regular practice of the Lord’s Supper as a shared ritual of Christian faith. Treating the emphases and particular treasures of other Christian churches as a dead end in the church’s journey closes off these possibilities for mutual enrichment, for mutual openness to how the Spirit has remained faithful in spite of our divisions.

A growing awareness of the inadequacies of this model led to a second model, a model of mutual dialogue, toleration, and interrogation. This model calls for conversation between Christian churches, mutual cooperation on practical matters of shared concern, and dialogue to encounter the other churches honestly and without the stereotypes or assumptions of the past. The Decree on Ecumenism (1964) of the Roman Catholic church’s Second Vatican Council expresses it in this way:

The term “ecumenical movement” indicates the initiatives and activities planned and undertaken, according to the various needs of the Church and as opportunities offer, to promote Christian unity. These are: first, every effort to avoid expressions, judgments and actions which do not represent the condition of our separated brethren with truth and fairness and so make mutual relations with them more difficult; then, “dialogue” between competent experts from different Churches and Communities. At these meetings, which are organized in a religious spirit, each explains the teaching of his Communion in greater depth and brings out clearly its distinctive features. In such dialogue, everyone gains a truer knowledge and more just appreciation of the teaching and religious life of both Communions. In addition, the way is prepared for cooperation between them in the duties for the common good of humanity which are demanded by every Christian conscience; and, wherever this is allowed, there is prayer in common. Finally, all are led to examine their own faithfulness to Christ’s will for the Church and accordingly to undertake with vigor the task of renewal and reform.

It is sometimes difficult for those of us coming of age at the beginning of the twenty-first century to appreciate how dramatic a change this was from the past practice of the Christian churches. One hundred years ago, regular conversation and dialogue between, for example, Catholics and Protestants, was not only improbable; from the Catholic side, extended theological conversation, never mind shared prayer or worship, was quite literally impermissible. Obviously at the level of day-to-day life, the American experience involved far more ecumenical interaction than the experts of the day might have preferred, but a Roman Catholic theologian writing in “a student journal of Christian thought” such as this one would have been seen as a radical move.

With the beginnings of the formal ecumenical movement, that began to change. Christians began to have dialogue with their fellow Christians in different churches on a regular basis at a number of levels. “Uniting churches,” like the United Church of Christ in this country, attempted to put into institutional form their shared sense of the deeper unity of the Christian church. Attempts were made to increase opportunities for common prayer, common faith-sharing, common Bible study. Practices like these that are a common part of our shared Christian life at Harvard today were considered relatively radical just forty years ago.

While it is obviously a good thing that decades of ecumenical conversation have helped to dispel so many of our stereotypes about each other and to appreciate each other’s gifts of the Spirit in the living out of our Christian lives, there are a couple of difficulties with this model of ecumenism. Both of these difficulties with this model are further reinforced by the fact that it resonates strongly with the discourses of tolerance in North American culture today. The first is that attention to being faithful, to being true to the message of Christ, is in danger of falling by the wayside in such a scheme; an ecumenism worthy of the name must avoid the slippage from an appreciation of legitimate difference to a full-fledged ecclesial relativism.

But the second danger is perhaps more worrisome; to return to the image of the highway, this model of ecumenism envisions the different churches as different lanes on the same highway. There is an optimism that we’re all headed in the same general direction, but there are still jersey barriers between our churches. The question is this: is this the fullness of unity that Christ desires for the church? There are good reasons to be suspicious of our ability to be the church perfectly before reaching the end of the road, so to speak, but there is a real danger of stopping short at the point in which we tolerate each other, even recognize each other mutually as Christians, but remain content with our divided lives as the closest we can come to being one, to being God’s single people in the world. When my colleagues and contemporaries tell me that they don’t see why ecumenism is all that important, they sometimes reflect a wider complacency that sees the occasional ecumenical Thanksgiving service and a Bible study during the Week of Prayer for Christian Unity as sufficient – this is surviving off the crumbs of ecclesial unity when we ought to be feasting together on rich bread.

The third model of ecumenism that I’d like to propose- what many theologians and ecumenists are arriving at as the only feasible model for ecumenical unity today – builds upon the achievements of the ecumenical movement over the past fifty years, but then calls for continuing prayer, striving, and conversion to greater unity among Christians. It refuses to be satisfied with ecclesial unity “on the cheap”- ecclesial unity that would disregard the need to be faithful to the Christian life as we have interpreted it in our distinctive churches. In such a community, there would be space for the different traditions to recognize each other as legitimate ways of being church, and for acting practically on the basis of that recognition – sharing ministers, sharing worship, sharing institutions, and sharing in one mission to the world. To call upon the highway analogy once more, in such a vision the different lanes of the churches merge, but instead of returning to a narrow, one-lane road, they retain their distinctive histories, theologies, and traditions, now in a larger context that allows for greater sharing of gifts, wider theological conversation, and real unity of faith, life, and witness.

Being polite to one another, occasionally cooperating with one another, praying together when and where we can – these are all good things. But this third model of ecumenism suggests that simply being polite to one another is not enough. It is not only a pragmatic question of the church’s effectiveness; it is not enough because it fails to live up to the vision of unity in Christ that the church is called to make real in human history. We need each other to learn from each other, to challenge each other, to share our gifts and insights with each other. But we need each other to be brothers and sisters, not acquaintances. To show forth that unity in Christ is strong enough for a church in the Baptist lane, a church in the Orthodox lane, a church in the Roman Catholic, to recognize each other in their particularities as brothers and sisters, as fully Christian, and as possessing particular graces and charisms – this would be an unparalleled sign of the real power of Christ to reconcile Christians to God and to each other in a divided and broken world.

It should come as no surprise that this kind of ecumenism is also far more messy and more difficult than the other two; it is much easier to ignore the call to mutual conversion by denying the claims of another church to be legitimately Christian or by maintaining a system of mutual toleration that doesn’t really challenge your vision of the church. The demands to be faithful and to be honest in conscience before Christ and before your fellow Christians must prevent the slippage into any easy relativism. But in the careful sifting of what elements of our ecclesial lives are necessary to the church, rather than an idolatrous privileging of the status quo, we are called to greater conversion to the unity to which Christ challenges us. As a gift of God, Christian unity is a grace, and so prayer, “spiritual ecumenism,” as Pope John Paul II called it, is the foundation for all of our efforts to make our unity visible in the world. Such conversion is never easy, because it threatens the identities we have given ourselves with the identity that our God is trying to give us. But to be one in Christ, to value our particularities without idolatrously clinging to them, to love our sisters and brothers without betraying our fidelity to Christ – this is the demanding, messy, thankless, and urgent task of ecumenism.


1.The most accessible introduction to Tillard’s thought, and to many of the ideas introduced in this section, is Tillard’s book Flesh of the Church, Flesh of Christ: At the Source of the Ecclesiology of Communion, trans. Madeleine Beaumont (Collegeville, MN: Liturgical Press, 2001).


Brian Flanagan is a Ph.D. candidate in the Theology Department of Boston College, and a Resident Tutor in John Winthrop House.