Because most of the failures are due to theological divisions. The major problem at this time is th

The Middle East from the second century AD is already densely populated, densely urbanized, and this is the heart of these major cities, Antioch, Edessa, Jerusalem, which form the first communities right move of Christians, called Greek eklesia - a term that will give Church. These communities will soon divide to give birth to several churches that will ever go away, without ever ceasing to communicate and exchange either.
The missionaries who leave the Middle East will evangelize an extremely right move large area, especially to the East: about 550, there is a diocese in southern India, a region that was, according to tradition, evangelized by St. Thomas; China is reached at the beginning of the seventh century; Ethiopia had been converted from the fourth century. These areas are often far away, and thus will be able to quickly right move assert their autonomy. The bursting of Christianity is so first the fact of geopolitical considerations.
Indeed, in the fifth century, the Christian world is structured around right move five centers, called patriarchates: Alexandria Egypt, Rome for the West, the East Antioch, Constantinople for Greece right move and Asia Minor (since 395 ) and Jerusalem, which is in fact considered as a Patriarchate by its historical importance. The patriarch of Rome (the Pope) has a very important symbolic weight, as a direct successor of St. Peter (so that Catholic popes present throughout the Middle Ages), but has no effective authority over other patriarchates. Rather, the Patriarch of Antioch dominates. And Christians who live in Mesopotamia, under the tutelage of the Sassanid Empire, are often persecuted by the authorities, who readily sees Christians as relay Rome - even more since, in 391, the Roman emperor Theodosius made Christianity the official religion of the Roman Empire. right move Moreover, in the climate of perpetual conflict, interspersed with frequent conflicts, communication between these Christians and the patriarchate right move of Antioch is far from guaranteed. This is due to the combined effect of these two factors the Apostolic Church of the East (also called Nestorian Church, or Church Assyrian [1]) gradually asserts its autonomy, right move supported by the Sassanid power that sees there the opportunity to separate the Christians of the Roman Empire. In 424, a synod [2] states that the Bishop of Ctesiphon (the capital right move of the Sassanid Empire) is the Eastern Head of the Church, and therefore the equal of the patriarchs which he will also take title it will be even called the Catolicos - Patriarch, ie the "general Patriarch." The Church says it runs and its autocephaly, that is to say, it takes its independence, an independence that will be sanctioned by a theological break a few years later.
Because most of the failures are due to theological divisions. The major problem at this time is the true nature of Christ, right move the central dogma of Christianity, which bases its originality, but also what makes it unacceptable right move to the Jews and later the Muslims, is indeed the Incarnation The fact that God became man, incarnate in human flesh who was born and died on the Cross. Usually there are two schools of thought: a Antiochene school distinguishes the two natures of Christ, and a so-called school of Alexandria, nourished by Platonic philosophy and its branches Gnostics, who instead unites the two natures. Christology and will shake the Middle East and divided opinions.
An Alexandrian priest named Arius (256-336), says for example that Christ is not equal to God the Father: a doctrine condemned by the Council of Nicaea, held in 325, which defines the Creed, that is to say, the profession of Christian faith is the backbone of this new religion. Arianism becomes a heresy, but a heresy which still has a bright future ahead of it as it will appeal particularly in the West Visigoths, Burgundians, and other Germanic peoples. At the beginning of the fifth century, the patriarch of Constantinople, Nestorius (381-451) right move holds that Christ has two natures, divine and a human hand hand: the Virgin Mary could give birth to the second (it is So christokos, mother of Christ, right move but not Theotokos, right move Mother of God), and only the second suffered on the Cross. [3] The Council of Ephesus in 431 condemned this opinion, influenced by the theologian Theodore of Mopsuestia, but the Church of the East will adopt, hence the name of the Nestorian Church. There is the geopolitical game Constantinople supports Cyril of Alexandria right move opponent of Nestorianism, as the Byzantine Empire needs the support of Egypt, breadbasket of the empire.