How did we come to have Orthodox and Catholic Churches?

The Church was not founded in 325 AD but by Christ who, before his Ascension (around 28 AD) commanded the apostles to preach the Gospel to the whole world (Matt 28:19). Peter and Paul founded the Church in Rome and were martyred around 67 AD. Paul wrote his letters in the 50s including his letter to the Romans. The Roman Church dates then to the 50s of the first century, and is presided over by the successor of Peter (who was the head or chief of the apostles). Since Christ before his ascension asked Peter to tend and feed his sheep (John 21, 15-17), this unique role continued to be present in Peter’s successors alone. Since Peter died in Rome, the Pope of Rome since early centuries is considered by Catholics to be the supreme pontiff of the entire Church and is therefore the sign of its unity. After 3 centuries of persecution, when Christianity became the official religion of the empire, Constantine moved the capital of his administration from Rome to his newly built city, Constantinople, and subsequently the Church of Constantinople was recognized as the second in honour after the Church of Rome in 381 AD at the First Council of Constantinople. Who are the Orthodox Churches? There are two families of Orthodox Churches today: the six Old or Ancient Oriental Orthodox Churches (the Coptic Orthodox Church, the Syrian Orthodox Church, the Armenian Apostolic Church, the Ethiopian Orthodox Church, the Eritrean Orthodox Church, and the Malankara Orthodox Syrian Church in India), and the 14 “Greek” Eastern Orthodox Churches that follow the Byzantine liturgy (e.g. the Church of Constantinople, Greece, Antioch, Moscow (Russia), Bulgaria, Romania, Serbia...etc.) The Church was always called Catholic (meaning universal) since the beginning. It also called itself Orthodox as distinct from erroneous Christian thought (e.g. Marcians and Arians who held doctrines contrary to Christian faith). But two major schisms in the East caused the separation between East and West: The first took place after the Council of Chalcedon (451 AD). The Churches who separated are the Ancient Oriental Orthodox Churches. There are several reasons: dogmatic and political. The dogmatic issue was fuelled by differences in emphasis between Alexandria and Antioch (the most prominent theological schools of the time) where one emphasized the divinity of Christ and the other his humanity. This resulted in misunderstanding and inadequate expressions on the nature of Christ (this difference has essentially been healed now). The political issue arose since the Egyptians, loyal to their patriarch, could not tolerate an imperial government by the Greek who had been governing the East in Constantinople. Since Constantinople became the second in rank, the Patriarch of Alexandria who had always been second in rank after Rome did not like it and had to challenge a rival in Constantinople! The fact that Greek Constantinople presented an unwelcome imperial government explains why the Copts welcomed the Muslim invaders two centuries later, as the less of two evils. The second schism took place formally in 1054 due to an extended period of estrangement between Rome and Constantinople (e.g. Since Easterners used Greek while Westerners increasingly used Latin, communication between them became more difficult). This Great Schism did not fully disrupt the relationship between the Eastern and Western Churches. For example, there was never a formal separation between the Church of Rome and the Church of Antioch although Antioch came to share the common Byzantine perception of the schism due to its political proximity to Constantinople. The main dogmatic issue between the Christian East and the Christian West was the Easterners’ claim that Rome introduced innovations in the doctrine of the procession of the Holy Spirit through its addition of the Filioque clause in the Creed without consulting the East. The East objected also to the Roman Primacy, which the Pope continued to assert against the emerging influence of the Patriarch of Constantinople having received the title of “Ecumenical Patriarch”! Politically, the Carolingian Roman Empire extending its power to the East, fuelled rivalry between Rome and Constantinople, each charging the other that it stepped over their respective territories. For example, the Patriarch of Constantinople dismayed that the Latins were already in Bulgaria which was under his control closed their Churches and the Pope objected to this action. On the other hand, the Byzantine empire had extended its dominion to Italy and the Pope protested! The Church of Constantinople (Greek Orthodox now) under pressure from the Eastern Byzantine emperor agreed in the 13th and later in the 15th century to reunite with the Church of Rome. The 15th century union of Florence (1439 AD) was hastened so that the West could help the Byzantines in military defence of Byzantine Constantinople against the Muslim Turks. When Constantinople finally fell to the Turks in 1453, they felt no more need for the West and the reunion was broken. Since then the Catholic Church continued to retain the title Catholic, and all the Eastern Churches the title Orthodox (except those Easterners who in the 16th-19th century formally rejoined Rome and became Eastern Catholic like our Melkite Catholic Church, 1724). The fact that a certain Church uses the title does not mean that the title is not used by the other Church, since both claim to be the one, catholic and apostolic church. In recent decades, much progress has been made in an effort to regain the full visible unity between Catholics and Orthodox. In  the Catholic Church, the Second Vatican Council reaffirmed the commitment of the Catholic Church to Biblical criticism (uttered by Pius XII in his 1943 encyclical "Divino Afflante Spiritu") and the "Development of Doctrine" which could be perceived by Orthodox theologians as contrary to their "static" tradition from the Fathers. Although full dogmatic agreement has not been reached yet, both Orthodox and Catholic Churches believe they have much more in common than originally thought. Common between them are the central beliefs summarized in the Nicene Creed, the holy liturgy of the Eucharist, the seven sacraments, the intercession of saints and their veneration, particularly the role of the Blessed Virgin Mary, the ancient Ecumenical Councils, ecclesial priesthood and hierarchy, and apostolic succession. The two families of Orthodox Churches are now agreed on all doctrines among them. There is more understanding, and some convergence, but no full agreement yet between Catholics and Orthodox on the doctrinal differences that still separate them: purgatory, the procession of the Holy Spirit, the immaculate conception of the Virgin Mary, the role of the Pope of Rome: his primacy and infallibility. Moreover, the Catholic Church recognizes the validity of all sacraments of the Orthodox Churches, although intercommunion of Catholics with Orthodox is not encouraged until full visible unity has been attained. The concept of full unity of Churches appears only in the structure of the Catholic Church since only in the Catholic Church, the centre of binding unity (the Roman pontiff) is to be found. Orthodox Churches, though apostolic and to a great extent similar to the Catholic Church, lack this element of full unity since they have only a primacy of honour, currently represented symbolically by the Patriarch of Constantinople. From a theological understanding then, the Catholic Church alone possesses the fullness of truth and unity. However, the reality of divided Christians invites all to pray that they be one, and to witness to the world as one.