Ecumenism is the word that de­­scribes the historical movement for global church unity. I used to think of it as either a boring academic exercise in doctrinal compromise, or a winner-takes-all struggle to forge one monolithic superchurch.

After five years in the field (I work for a Lutheran ecumenical organization), I'm no longer dismissive. The quest for church unity is a wild, wondrous, and strange act of penitence for Christians' often callous disregard of that little word one in John 17 and the Nicene Creed. We confess that the Holy Spirit has called one church into being. But almost all the evidence points in the opposite direction. What does this mean? And how should we respond to it?

Coping with Division

Throughout church history, Christians have come up with many ingenious ways of explaining why the one church can be divided into many factions. The easiest, of course, is to say that everyone outside of a particular circle is not actually part of the church. That was how the church father Cyprian dealt with it: By definition the church is one, indivisible; so if there appear to be "divisions," the reality is simply the true church versus a wicked pretender. And outside the church, there is no salvation.

But this approach works only if the isolation is strictly maintained. What happens if Christians in one "church" encounter those of another "church" and are startled to find genuine faith, piety, and good works?

At this point the more generous but almost as problematic notion of the "invisible church" comes in. It's usually based on Jesus' parable about the wheat and the tares. The basic idea is that godliness describes only individuals, not institutions. We all know that our church is full of inauthentic Christians. Meanwhile, we've discovered that their church actually has some authentic ones. Therefore, the one true church is invisible, known only to God. Visible, historical communities are merely incidental to the business of being the real church.

These may seem like opposite solutions to the unity problem: one maximizes the importance of church structures, and the other minimizes it. But underlying both is a refusal to take church history seriously. And that's a problem.

If there's any doctrine that must take real, lived history into account in order to be meaningful, it's ecclesiology, the doctrine of the church. But both approaches ignore inconvenient historical realities. Defining a specific church as the church ignores the Holy Spirit's capacity to move beyond boundaries and structures created by humans. But defining the church as authentically Christian individuals, wherever they are, reduces structural divisions to matters of indifference, when in reality they foster hostility among those who should be calling each other brother and sister. The protracted religious wars in 16th- and 17th-century Europe were proof enough that the notion of an "invisible church" couldn't stop Christians from killing each other.

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Embarrassingly enough, Chris­tians did not theologically confront their internal violence until outsiders called them out on it. It was the experience of competing on the mission field that exposed the hypocrisy (dare we say heresy?) of competing factions, all claiming to be the supreme bearers of the truth and love of Christ. Potential converts were not impressed, and the missionaries knew it.

No Successful Model

The result, at the famous Edinburgh Missionary Conference of 1910, was the birth of the ecumenical movement. The primary goal was not fattening up an underdeveloped doctrine or even reducing intra-Christian hatred. It was about making a credible witness to those who did not yet believe in Christ. "By this all people will know that you are my disciples, if you have love for one another," Jesus said (John 13:35, ESV). But what if the disciples don't love each other, and even build up walls to keep it that way? Disunity is a scandal to the gospel and a stumbling block to faith.

On the night of his arrest, Jesus prayed three times to the Father on behalf of his disciples "that they may be one as we are one" (John 17:11, 21–22). The desire to uphold that prayer has been the driving force of the ecumenical movement. But the way forward has hardly been obvious. The oneness of the church has proved to be a paradox like the other great paradoxes of faith: the humanity–divinity of Christ, the already–not yet of salvation, the sinner–saint reality of the believing Christian. The church is divided and yet somehow still one.

No single proposal for unity has won out. One difficulty is that each Christian community tends to create a model that reflects its own preexisting concept of the church, which is in turn based on the peculiarities of its history. It's a truism by now that Catholicism absorbed the model of the Roman Empire, Eastern Orthodoxy took after the tight state-church alliances in its areas of origin, and Reformation-era Protestants embraced a growing separation between sacred and secular authority.

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The same pattern continues today. Evangelicals and Pentecostals, in their penchant for dividing and subdividing, mirror the capitalist market in providing a product for every taste. Mainline Protestants follow a franchise model, with each congregation expected to be the outpost of a central headquarters. Unity secured through networks of congregations and parachurch ministries reproduces the inter­connectedness of the Internet. The freedom of migration from one Christian community to the next reflects an economy and society based on individual preferences and opportunities.

None of this means that these models of church are necessarily wrong. But it does show that churches mimic the kind of unity they see around them. It's worth asking whether a truly ecumenical model of church unity—as opposed to a denominational or a worldly one—even exists yet.

Though they haven't solved the problem of disunity, ecumenical efforts have made a difference. Pan-Christian solidarity played a vital role in ending Communism in Eastern Europe and apartheid in South Africa. It has fostered joint service projects between Christians who previously wouldn't have trusted each other with their money. And through careful dialogue, it has discovered the astonishing commonality among Christians—far more than an emphasis on divisive issues would lead anyone to believe. At its best, ecumenism seeks to hold together matters of doctrine, church governance, and missional outreach.

Back to the Beginning

It would be tempting to blame some particular person or party for church division—somebody who disrupted the ancient harmony with false teaching or bad behavior. But that disunity began in the pages of Scripture.

Dissension within the church started early. Think of the break between Paul and Barnabas, the conflict between Peter and Paul, the unjust Communion practices at Corinth, and the false teachers who led the faithful astray. Paul endlessly exhorted his fellow disciples to love each other, as did John. They wouldn't have had to repeat themselves had unity been happening naturally and automatically.

There are many reasons for internal conflict, some sinful and some legitimate (though nearly everyone thinks their reasons are legitimate and only minimally sinful). But Paul makes an important distinction: While he acknowledges that "there must be factions among you in order that those who are genuine among you may be recognized" (1 Cor. 11:19, ESV), there must be "no divisions among you" (1:10). The Greek word there is schismata, from which we get "schism." And the reason is that "in one Spirit we were all baptized into one body—Jews or Greeks, slaves or free—and all were made to drink of one Spirit" (1 Cor. 12:13, ESV).

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Church turns divisive and ideological when it is severed from the gospel that brought it into being. And at its most simple and radical, the gospel is this: "While we were still sinners, Christ died for us" (Rom. 5:8). God came after sinners who wanted nothing to do with their Creator, gathering up a community of enemies and making them into a family, a fellowship, a church. The church is the epicenter of enemy reconciliation in the world, starting with the severest estrangement possible—between God and human beings—and working out from there to repair all forms of human estrangement.

This sort of gospel has incredible social consequences. In the New Testament, it united Jews and Gentiles. After ten chapters of Jewish-only missions in Acts, Peter is suddenly confronted first with a vision and then with the pious Gentile Cornelius, who comes to faith in Christ so fast that Peter can't even finish his sermon. The brothers back home in Jerusalem were none too pleased to hear that the "unclean" had been baptized. But Peter countered, "If then God gave the same gift to them as he gave to us when we believed in the Lord Jesus Christ, who was I that I could stand in God's way?" That silenced their objections, allowing their disbelief to give way to a bigger and bolder faith: "Then to the Gentiles also God has granted repentance that leads to life" (Acts 11:17–18, ESV).

The Pauline communities later came to understand the intrinsic link between the gospel and the church: Christ "himself is our peace, who has made us both one and has broken down in his flesh the dividing wall of hostility" (Eph. 2:14, ESV). A mere invisible unity wouldn't do justice to the Cross. Its results had to be shown in the real, visible, lived fellowship between old enemies.

Love the Heretic, Hate the Heresy

There is a serious objection to all of this and to ecumenism itself. What if enemies of Christ have snuck inside the gates? False teachers were condemned and sent away by the apostles; shouldn't we do the same? Isn't division preferable in certain cases?

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The matter finally comes down to how we view the "enemy" that the false teacher has become. Is the heretic an enemy like Satan, to be thrown into the lake of fire and tormented forever? Or one of the lost sheep whom Christ goes to great lengths to rescue, the ungodly for whom Christ died? The truth is, no heretic will recover from his heresy as long as the orthodox permanently reject him. And there's always the possibility that buried beneath the heresy is a neglected shard of truth. Lutheran theologian Arthur Carl Piepkorn liked to say that heresies were Bußpredigten, meaning "repentance sermons": They were rebukes to the mainstream church for overlooking some aspect of Christian truth and love.

Sticking with enemies and heretics is not for the faint of Spirit. It means forgiving seventy times seven. It means humbly counting others more significant than yourself. It means blessing, not cursing, those who persecute you. It means, in short, doing unto others as Christ has done unto you.

Why Try?

Many still doubt the importance of unity. Often that's because of false perceptions about what unity might actually entail. And often it's due to a sinful protectiveness regarding one's own corner of Christen­dom. But refusing to strive toward unity is like saying, "Why bother trying to be holy when God has already declared us righteous?" God has given us the gift of salvation; we can live in contradiction to that gift, or we can be transformed by it into holy people. Likewise, God has called one church to be the one body of Christ; we can live in contradiction with that one church, or we can reconcile and make visible our unity in Christ.

In the end, it's not a matter of what we think would be best for the world or for the advancement of Christianity. It's simply a matter of living into Jesus' prayer for us: "that they may be one."

Sarah Hinlicky Wilson is assistant research professor at the Institute for Ecumenical Research in Strasbourg, France, and the editor of Lutheran Forum.

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