In January of 1964 Pope Paul VI of Rome and Patriarch Athenagoras of Constantinople embraced each other in the holy city of Jerusalem. They prayed that God would inaugurate an era of love and reconciliation between the world’s Roman Catholic and Eastern Orthodox Christians. In the 15 years following this historic meeting, the first such encounter between the leading bishops of the Roman Catholic and Orthodox Churches since 1439, efforts have been made on all levels of churchly life for Roman Catholics and Orthodox to rediscover the unity in Christian faith and love which once existed between them.

The Orthodox Church today consists of the ancient patriarchates of Jerusalem, Alexandria, Antioch and Constantinople, the last of which is called the Ecumenical Patriarchate, since Constantinople (now Istanbul in Turkey) was once the capital city of the Roman and Byzantine Empire. The Patriarch of Constantinople exercises the office of leader of world Orthodoxy in that he presides over all affairs having to do with the Orthodox churches throughout the world. The bishop of Constantinople, however, as the Ecumenical Patriarch in the East, cannot be equated with the bishop of Rome in the West as he has none of the powers of jurisdiction within the Orthodox Church that the Pope of Rome has in the Roman communion.

In addition to the four ancient patriarchates, there are in the Orthodox family of churches the newer patriarchates of Russia, Serbia (in Yugoslavia), Romania and Bulgaria; and there are also the ancient, self-governing churches of Georgia (or Iberia, in the USSR) and Cyprus; as well as the more recently established churches of Greece, Albania (declared nonexistent by the socialist government of the country), Poland, Czechoslovakia and America.

These fifteen self-governing churches form the world family of Orthodox Churches. They all confess the same doctrines, worship with the same liturgical rites, regulate their lives by the same church discipline, and nurture their members with the same spiritual tradition. They form one ecclesiastical communion. They identify their faith and life with that of the apostolic church of Christ. They claim to express an unbroken succession of catholic Christian faith and order from the apostolic church to the present day.

The central affirmation of the Orthodox Church is that the one true and living God who created heaven and earth is the God of Israel and the Father of Jesus Christ. Orthodox believe that Jesus Christ existed eternally with God before creation as His uncreated Son, Word and Image; that He is the one by, in and for whom all things were made; and that He was born into the world as a real human being by the Virgin Mary as the promised messiah of Israel and the savior of the world.

Orthodox believe as well that God has with Himself from all eternity not only His only-begotten Son, but also His most Holy Spirit who “proceeds from the Father” and is divine with exactly the same divinity as that of God the Father and the Son. The Holy Spirit is God’s power and breath who empowers the creation of the world, who speaks in the law and the prophets of Israel, who inspires the writing and the interpreting of the Bible, and who is in and on Jesus, showing Him to be God’s eternal Son in human flesh who saves the world and gives the same Spirit to all who believe in His Name.

In Christ all is saved, all is transfigured; all is restored, recreated and renewed. Everything in the Orthodox Church bears witness to this affirmation: the sacraments and symbols, the doctrines and dogmas, the scriptures and the saints, the icons and the hymns. Everything proclaims the fact that in Christ and the Holy Spirit all things are made new and that Christ reigns as king over the creation which is His, given by God and sanctified by the Spirit. It is in this sense that the Orthodox believe the Church to be the kingdom of God on the earth, and proclaim that all men and women are created by God for life in this kingdom, in which they find their true value and beauty, their dignity, and their very being and life.

The separation which exists today between Roman Catholics and Eastern Orthodox came about in the eleventh century because of theological disagreements, cultural divergencies and political disputes. These differences were sealed and hardened by the Western crusaders’ pillaging of Eastern Christian churches in the twelfth and thirteenth centuries and by the fall of the East to the Turks.

Orthodox and Roman Catholic theological disagreements center around the understanding of the nature of God and His Church. The Orthodox fault the Roman Catholics for changing the creed of Nicea by adding the words “and from the Son” (filioque) to the statement of faith which says that the Holy Spirit “proceeds from the Father.” According to the Orthodox, it is an unnecessary and unlawful changing of the Nicene creed and an incorrect description about the relationship of the Holy Spirit to God the Father and to His only-begotten Son. Many debates have taken place on this issue since the eleventh century, and efforts are being made today, in the spirit of friendship and mutual respect, to solve this problem for the sake of doctrinal and churchly unity.

In addition to the theological problem about the creed and the procession of the Holy Spirit, the Orthodox also disagree with the doctrine that the bishop of Rome has special powers given by God and transmitted in the Church from the apostle Peter. Because of this, Orthodox Christians reject the doctrine of papal infallibility which was proclaimed by Vatican Council I. The question of the authority of the bishop of Rome contributed to the division between the Churches in the eleventh century, and it continues to separate Roman Catholics and Orthodox today.

Other differences that exist between the two Churches include the manner of understanding and venerating the Virgin Mary (Orthodox deny the dogma of the Immaculate Conception); the manner of celebrating the Holy Eucharist; the manner of exercising authority and governing the church; and the problem of certain sacramental and devotional practices and teachings.

Despite their differences, however, Eastern Orthodox and Roman Catholics share belief and tradition in many aspects of Christian doctrine. The greatest problem between them remains that of estrangement and ignorance. And this problem, by God’s grace and the goodwill of men, is being overcome in our time.

Father Hopko is a professor of theology at St. Vladimir’s Seminary in Crestwood, N.Y. and pastor of St. Nicholas Orthodox Church in Jamaica Estates, N.Y.