AN HISTORICAL INTRODUCTION TO ORTHODOXY: The New Testament Church was founded by Jesus Christ and preached by the Apostles. Its beginning dates back to Pentecost, 33 A.D. The Patriarchate of Antioch, for example, was originally founded in A.D. 34 by Saint Peter and Saint Paul, and is referenced in the Bible Acts 11, verses 25 to 27, as follows:
25. Then Barnabas went to Tarsus to look for Saul,
26. and when he found him, he brought him to Antioch. So for a whole year Barnabas and Saul met with the church and taught great numbers of people. The disciples were called Christians first at Antioch.
27. During this time some prophets came down from Jerusalem to Antioch.
The basic structure of the early Church was that of a universal union of local churches bound by the unity of apostolic succession of the bishops. Each church community was organically a part of the universal unity of all Christians as one people of God. By the year 1,000, the New Testament Church had become communities of local churches organized around five regional centers; each headed by a “Patriarch” – the Patriarchates of Constantinople, Alexandria, Antioch, Jerusalem, and Rome. But it was still a single Christian church, united in faith and practices.
There was some friction, even at an early stage, about the status of the Church of Rome, - which was the Church of the apostles Peter and Paul, and the Church of the capital of the Empire. In the East, Rome was given the ceremonial title of “First among Equals”. However, in Rome, the Popes began to declare that special God-given rights had been granted to the papacy to govern the universal church. The rest of the Church rejected those claims.
However, the Popes continued to expand and pursue their claims of authority over the entire Christian Church. In 1054, the Pope severed his ties with the other Patriarchs in the East. After that, the Popes in Rome instituted changes in beliefs and practices that were rejected by the Orthodox Patriarchs in the East, who continued to preach and practice the original Christian faith. These Roman changes were so onerous that Martin Luther ignited the Protestant Revolution that raged throughout Europe. But rather than returning to the original Christian faith, the Protestants repeated the errors of the Popes by instituting further changes in beliefs and practices in the name of Christianity. This led to further splintering of the Protestant ranks. It is estimated that there are now over 25,000 different Protestant denominations in the United States alone.
(borrowed with permission from the website of Forty Holy Martyrs of Sebaste Antiochian Orthodox Church)