The Orthodox Church respects and preserves the canons and the decisions of the seven Ecumenical Councils, rejects and does not recognize the universal authority of the Pope. Today it's organized on a national level.
The Orthodox Church is not one church but a family of independent bodies which are referred to by the nations in which they are located (Greek Orthodox Church, Russian Orthodox Church...) They are united in the understanding of the sacrament, doctrine, liturgy, ecclesiastical order, but each of them alone regulates its life. At the head of each Orthodox Church a Patriarch was appointed as the Head of. Chief among them is the Patriarch of Constantinople with the headquarters in Istanbul, which enjoys considerable favor, but no power to influence other Orthodox churches, being only the first among equals.
The Orthodox Church claims to be the only true church of Christ, and that its roots go back to the first apostles. They believe in the Trinity, the Bible as the word of God, Jesus as the Son of God and other biblical doctrines.
The most important work on which the liturgy is based, is the Holy Bible made of the Old and the New Testament, as well as Sacred Tradition. The New Testament is particularly significant for Orthodoxy which presents the life and teachings of Jesus Christ.
The most important role of the Orthodox churches is to serve as a place where the living Church - the believers, cry aloud their prayers to God. The most important part of church life is sacred liturgy i.e. religious services, served on Sundays and other holidays at the temples. In addition to the liturgy, the morning and evening prayer are performed , classes and vigils also, which have instructive character at the same time. Liturgy is served by a priest in the presence of believers. There are three levels of the ministry: a deacon, a priest and a bishop. Episcopes or Bishops are hierarchically below the patriarchs and their administrative units called dioceses.