The Orthodox Church was founded by our Lord Jesus Christ and is the living manifestation of His presence in the history of the mankind. Orthodox Christianity is characterized by its rich liturgical life and its faithfulness to the apostolic tradition. It is believed by Orthodox Christians that their Church has preserved the tradition and continuity of the ancient Church in its fullness. Today the Orthodox Church numbers approximately 300 million Christians who follow the faith and practices that were defined by the first seven ecumenical councils. The word orthodox ("right belief / right worship") has traditionally been used to designate communities, or individuals, who preserved the true faith.

The Orthodox Church is a family of "autocephalous" (self governing) churches, with the Ecumenical Patriarch of Constantinople holding titular or honorary primacy as primus inter pares (the first among equals). The unity of the Church is rather manifested in common faith and communion in the sacraments. The number of autocephalous churches has varied in history. Today there are many: the Church of Constantinople (Istanbul), the Church of Alexandria (Egypt), the Church of Antioch (with headquarters in Damascus, Syria), and the Churches of Jerusalem, Russia, Serbia, Romania, Bulgaria, Georgia, Cyprus, Greece, Poland, Czechlands and Slovak, Albania, and America.

There are also "autonomous" churches (retaining a token canonical dependence upon a mother see) in Sinai, Crete, Finland, Japan, China and Ukraine. In addition there is also a large Orthodox Diaspora scattered all over the world and administratively divided among various jurisdictions. In the wider theological sense "Orthodoxy is not merely a type of purely earthly organization which is headed by patriarchs, bishops and priests who hold the ministry in the Church which officially is called "Orthodox." Orthodoxy is the mystical "Body of Christ," the Head of which is Christ Himself, and its composition includes not only clergy but all who truly believe in Christ, who have entered into the Church He founded, those living upon the earth and those who have died in the Faith and in piety.

The Orthodox Church is well known for its developed monasticism. The uninterrupted monastic tradition of Orthodox Christianity can be traced from the Egyptian desert monasteries of the 3rd and 4th centuries. Soon monasticism had spread all over the Mediterranean basin and Europe: in Palestine, Syria, Cappadocia, Gaul, Ireland, Italy, Greece and Slavic countries. Monasticism has always been a beacon of Orthodox Christianity and has made and continues to make a strong and lasting impact on Orthodox spirituality.

The Orthodox Church today is an invaluable treasury of the rich liturgical tradition handed down from the earliest centuries of Christianity. The sense of the sacred, the beauty and grandeur of the Orthodox Divine Liturgy create a sense of the presence of heaven on earth. Orthodox Church art and music enable the bodily senses to feel the spiritual grandeur of the Lord's mysteries. Orthodox icons are not simply beautiful works of art which have certain aesthetic and educational functions. They are a means through which we experience the reality of the Heavenly Kingdom on earth.

Excerpt taken and adapted from The Orthodox Church by Bishop Kallistos (Ware).