Who are the Eastern Churches?
Jesus Christ commanded his apostles to preach the "good news" to the whole world. St. Peter traveled from Jerusalem to Antioch and then to Rome. St. Andrew founded the Church in Byzantium which later became Constantinople. St. James went to Egypt and St. Thomas to India. Of the five initial Patriarchates, known as the Pentarchy, the four in the Eastern half of the Roman Empire are the origins of what are today called the Eastern Churches.
Where are they located?
The centers of early Eastern Christianity were Jerusalem, Antioch, Alexandria and Constantinople. The fifth city of the Pentarchy was Rome from which Western Christianity developed. Today, Eastern Christianity has spread throughout the world, because of the immigration of ethnic groups from the Middle East, Asia, and Eastern Europe to other continents and other civilizations. Large concentrations are still located in the homelands, but additional ecclesiastical jurisdictions now exist in most areas of the world.
How are they distinct?
The Eastern Churches, both Catholic and Orthodox, follow traditions that are traced to the earliest Church. The Divine Liturgy uses a great deal of symbolism, representing heaven on earth with singing, incense, and visual effects. The sacraments of Baptism, Chrismation (Confirmation), and Eucharist are celebrated as a single Rite of Christian Initiation. Most churches join the Holy Altar with the nave by an icon screen on which Christ, the Mother of God, and various saints are depicted. Spirituality and monasticism are focal points for the Eastern Churches, and provide a close link between the faithful, religious and clergy.