A long and continuing trail of broken relations among Christians began in the 2nd century when the gnostics presented a serious doctrinal error and broke fellowship. Quartodecimanism, a dispute over the date of Easter, pitted Christians from Asia Minor against those from Rome. Montanism—which taught a radical enthusiasm, the imminent Second Coming of Christ, and a severe perfection, including abstinence from marriage—split the church. The Novatians broke fellowship with Christians who had offered sacrifices to pagan gods during the persecutions by the Roman emperor Decius in 250 ce. In the early 4th century the Donatists, Christians in North Africa who prided themselves as the church of the martyrs, refused to share communion with those who had lapsed—i.e., those who had denied the faith under threat of death during the great persecutions of Diocletian and Galerius. The Donatists remained a powerful force in Africa into the 5th century and survived into the 7th despite opposition from church and state. This schism—like many since—reflected regional, national, cultural, and economic differences between the poor rural North African Christians and the sophisticated urban Romans.
In each century, leaders and churches sought to reconcile these divisions and to manifest the visible unity of Christ’s church. But in the 5th century a severe break in the unity of the church took place. The public issues were doctrinal consensus and heresy, yet, in the midst of doctrinal controversy, alienation was prompted by political, cultural, philosophical, and linguistic differences. Tensions increased as the church began to define the relationship between God the Father and God the Son and later the relation between the divine and human elements in the nature and person of Jesus Christ. The first four ecumenical councils—at Nicaea (325 ce), Constantinople (381), Ephesus (431), and Chalcedon (451)—defined the consensus to be taught and believed, articulating this faith in the Nicene Creed and the Chalcedonian Definition, which stated that Jesus is the only begotten Son of God, true man, and true God, one person in “two natures without confusion, without change, without division, without separation.”
Some groups deviated doctrinally from the consensus developed in the councils. " class="md-crosslink">Nestorianism, which came to be regarded as a heresy at Ephesus, taught that there are two distinct persons in the incarnate Christ and two natures conjoined as one. " class="md-crosslink">Monophysitism, regarded as a heresy at Chalcedon, taught that there is one single, divine nature. Several churches refused to accept the doctrinal and disciplinary decisions of Ephesus and Chalcedon and formed their own communities largely outside what was considered the mainstream of Christianity in Europe and in parts of the Middle East. The Nestorian movement became the Assyrian Church of the East. Several churches that rejected the outcome of Chalcedon were (incorrectly) branded as monophysites. Despite some attempts at reconciliation, both the Nestorian and the alleged monophysite churches were cut off from the Roman Catholic, Eastern Orthodox, and (later) Protestant churches until the ecumenical movement of the 20th century. Yet, like their European counterparts, they became great missionary churches and spread throughout Africa and Asia. The Schism of 1054
The greatest schism in church history occurred between the church of Constantinople and the church of Rome. While 1054 is the symbolic date of the separation, the agonizing division was six centuries in the making and the result of several different issues. The Eastern church sharply disagreed when the Western church introduced into the Nicene Creed the doctrine that the Holy Spirit proceeds not from the Father alone—as earlier Church Fathers had taught—but from the Father and the Son (Latin: Filioque). When the Roman Empire was divided into two zones, Latin-speaking Rome began to claim superiority over Greek-speaking Constantinople, and disputes arose over church boundaries and control (for example, in Illyricum and Bulgaria). Rivalry developed in Slavic regions between Latin missionaries from the West and Byzantine missionaries from the East, who considered this territory to be Orthodox. Disputes over authority became even more heated in the 11th century as Rome asserted its primacy over all churches. Lesser matters related to worship and church discipline—for example, married clergy (Orthodox) versus celibacy (Roman Catholic) and rules of fasting and tonsure—strained ecclesial relations. The tensions became a schism in 1054, when the uncompromising patriarch of Constantinople, Michael Cerularius, and the uncompromising envoys of the pope St. Leo IX excommunicated each other. No act of separation was at this time considered final by either side. Total alienation came a century and a half later, as a result of the Crusades, when Christian knights made military campaigns to save Jerusalem and the Holy Land from the Muslims. In 1204 the Fourth Crusade was diverted to attack and capture Constantinople brutally. Thousands of Orthodox Christians were murdered, churches and icons were desecrated, and undying hostility developed between East and West.
Schism of 1054Map of the Schism of 1054.Encyclopædia Britannica, Inc./Kenny Chmielewski
Even so, certain leaders and theologians on both sides tried to heal the breach and reunite East and West. In 1274, at the second Lyon" class="md-crosslink">Council of Lyon, agreement was reached between the two churches over several key issues—Orthodox acceptance of papal primacy and the acceptance of the Nicene Creed with the Filioque clause. But the agreements were only a rushed action conditioned by political intrigue. As a result, reunion on these terms was fiercely rejected by the clergy and laity in Constantinople and other Orthodox provinces. A second attempt at reunion came at the Council of Ferrara-Florence that met in Italy in 1438 and 1439. A formula of union was approved by both delegations, but later it was rejected by rank-and-file Orthodox Christians. The Reformation
The next dramatic church division took place during the Reformation in the West in the 16th century. Like other schisms, this one does not yield to simple analysis or explanation. The Reformation was a mixture of theology, ecclesiology, politics, and nationalism, all of which led to breaks in fellowship and created institutional alienation between Christians throughout Western Christendom. In one sense it was a separation, especially a reaction against the rigid juridical structures of medieval Roman Catholicism and its claim to universal truth and jurisdiction. In another sense, however, the Reformation was an evangelical and ecumenical renewal of the church as the Body of Christ, an attempt to return to the apostolic and patristic sources in order, according to John Calvin, “to recover the face of the ancient Catholic Church.” All the Continental reformers sought to preserve and reclaim the unity of the church.
Once the separation between the Roman Catholic and new Protestant churches was complete, people on both sides tried to restore unity. Roman Catholics such as Georg Witzel and George Cassander developed proposals for unity, which all parties rejected. Martin Bucer, celebrated promoter of church unity among the 16th-century leaders, brought Martin Luther and his colleague Philipp Melanchthon into dialogue with the Swiss reformer Huldrych Zwingli at Marburg, Germany, in 1529. In 1541 John Calvin (who never ceased to view the church in its catholicity), Bucer, and Melanchthon met with Gasparo Cardinal Contarini and other Roman Catholics at Ratisbon (now Regensburg, Germany) to reconcile their differences on justification by faith, the Lord’s Supper, and the papacy. Another attempt was made in 1559, when Melanchthon and Patriarch Joasaph II of Constantinople corresponded, with the intention of using the Augsburg Confession as the basis of dialogue between Lutheran and Eastern Orthodox Christians. On the eve of the French wars of religions (1561), Roman Catholics and Protestants conferred without success in the Colloquy of Poissy. It would seem that the ecumenical projects of theologians and princes in 16th-century Europe failed unequivocally, but they kept alive the vision and the hope. Ecumenism in the 17th and 18th centuries