This question is an ancient, and difficult, one. Before we can project how Christian unity might take shape in the future, we should look at how Christians have dealt with unity, schisms, and ecumenism in the past.

In A.D. 402, Augustine pled with the breakaway Donatists: "Why have you severed yourselves, by the heinous impiety of schism, from the unity of the whole world?" He challenged their disdain of the catholic, or universal, church with an accusation of his own. "But you, by charging the good wheat [the Catholic church] with being tares, have proved yourself to be tares; and what is worse, you have prematurely separated yourselves from the wheat." He enjoined them to return to the Church: "Awake to the interest of your salvation! Love peace, and return to unity!"

The Donatists ignored Augustine's plea, and his call to unity has gone unheeded for centuries. Church councils sought to reconcile factions to each other, by arriving at an orthodoxy consistent with Scripture and satisfactory to most, if not all. Instead, divisions deepened, beginning with the Council of Nicea, which drove a wedge between Constantine's Church and the "heretical" Arians. Later, Monophysites from Egypt, Nestorians from Syria, and, in Augustine's time, Donatists from Carthage, broke away from the Catholic church, as these new "sects" claimed their own turf.

Unfortunately, Christians have divided along territorial lines ever since. In 865, Pope Nicholas's claim to authority "over all the earth, that is, over every church," didn't sit well with the patriarch in Constantinople. Eastern and Western attempts to foster cooperation and understanding suffered another setback when missionaries began competing for converts in Bulgaria. A Western addition to the Nicene Creed alienated Constantinople even more. Then, in 1054, the pope and patriarch excommunicated each other. When Crusaders sacked Constantinople in 1204, all efforts to reconcile the two sides ended.

When Martin Luther posted his 95 theses in Wittenberg on All Saints Eve, 1517, he meant only to challenge the Catholic church's practice of selling indulgences. But Luther's theses gave Germany's princes reason to question the Church's authority, and the Protestant Reformation divided Europe yet again. Holland became a safe haven for Anabaptists, Geneva for Calvinists. Henry VIII broke England away from the Church when the pope refused to recognize his divorce. The Council of Trent, intermittently in session from 1545 to 1563, ended any hope of reconcilation by affirming doctrines Protestants rejected: justification by faith and works, tradition as co-equal with Scripture, and the practice of indulgences, among others.

It's beyond the scope of our survey to recount the many schisms that have divided Protestants over the centuries. Suffice it to say, Protestants have witnessed a proliferation of denominations and sects, especially in the twentieth century. Yet in the name of Christian unity, Protestants have also made serious efforts to dialogue and, where possible, cooperate. Considered the "father of the ecumenical movment," John R. Mott helped lay the groundwork for the World Council of Churches, formed in 1948. Other movements followed, including the World Evangelical Fellowship (renamed the World Evangelical Alliance). In 1996, Lutherans and Episcopalians explored the possibility of recognizing each other's bishops, though some Lutherans expressed concern that Episcopalians would not have to susbcribe to the (Lutheran) Augsburg Confession.

Protestants and Catholics have also begun dialoguing, especially since Pope John XXIII appealed to non- Catholics as his "separated brethren" at Vatican II. In November, 1999, the Roman Catholic Church and the Lutheran World Federation signed a joint declaration on the doctrine of justification, paving the way for reconciliation of the churches. Even the Orthodox Church showed signs of ecumenism with the signing of the Charta Oecumenica in April, 2001, by an Orthodox metropolitan and a Catholic cardinal.

Given today's spirit of consumerism and entrepreneurship, it does seem unlikely that ecumenism can outpace the splintering of denominations we are now witnessing. Some Christians concede organizational unity may be a hopeless cause, but say that the Church can achieve what Jesus intended — spiritual unity. Evangelical churches, which tend to be less hierarchical and more flexible, have shown a good deal of unity through shared mission and ministry. What is clear is that we must continue to pray as Jesus did in John 17: "My prayer is not for them alone. I pray also for those who will believe in me through their message, that all of them may be one. … (NIV)"

  1. Past Christian History issues cover in detail many of the events mentioned here. For an in-depth look at the heresies Augustine and other Church fathers opposed, click on We covered Augustine's life and work in issue 67: For a detailed survey of Eastern Orthodoxy and the story of the Orthodox-Catholic split, check out To understand the political as well as theological importance of the Protestant Reformation, order issue 34: Martin Luther, The Early Years.
  1. To read Augustine's letter to the Donatists, go to
  2. For a quick summary and the text of the bull promulgated by Pope Paul III shortly before the Council of Trent, click on
  3. For an introduction to ecumenism in the twentieth century, check out:
    Christianity Today covered ecumenism online, including articles on a Lutheran-Episcopal concordant:,
    Lutheran-Catholic dialogue:,
    an Orthodox-Catholic charter:,
    and an analysis of the World Council of Churches and the World Evanglical Alliance:
    To read more articles, simply enter "ecumenism" into the search box.

Steven Gertz is editorial coordinator for Christian History