Orthodox Christianity is the life in faith of the Orthodox Church, inseparable from that concrete, historic community and encompassing its entire way of life. The Orthodox Christian faith is that faith “handed once to the saints” (Jude 3), passed on in Holy Tradition to the apostles by Jesus Christ, and then handed down from one generation to the next, without addition or subtraction.
The sole purpose of Orthodox Christianity is the salvation of every human person, uniting him to Christ in the Church, transforming him in holiness, and imparting eternal life. This is the Gospel, the good news, that Jesus is the Messiah, that he rose from the dead, and that we may be saved as a result.
Orthodox Christians worship the Father, Son, and Holy Spirit—the Holy Trinity, the one God. Following the Holy Scriptures and the Church Fathers, the Church believes that the Trinity is three divine persons (hypostases) who share one essence (ousia). It is paradoxical to believe thus, but that is how God has revealed himself. All three persons are consubstantial with each other, that is, they are of one essence (homoousios) and coeternal. There never was a time when any of the persons of the Trinity did not exist. God is beyond and before time and yet acts within time, moving and speaking within history.
God is not an impersonal essence or mere “higher power,” but rather each of the divine persons relates to mankind personally. Neither is God a simple name for three gods (i.e., polytheism), but rather the Orthodox faith is monotheist and yet Trinitarian. The God of the Orthodox Christian Church is the God of Abraham, Isaac and Jacob, the I AM who revealed himself to Moses in the burning bush.
The source and unity of the Holy Trinity is the Father, from whom the Son is begotten and also from whom the Spirit proceeds. Thus, the Father is both the ground of unity of the Trinity and also of distinction. To try to comprehend unbegottenness (Father), begottenness (Son), or procession (Holy Spirit) leads to insanity, says the holy Gregory the Theologian, and so the Church approaches God in divine mystery, approaching God apophatically, being content to encounter God personally and yet realize the inadequacy of the human mind to comprehend him.
The primary statement of what the Church believes about God is to be found in the Nicene-Constantinopolitan Creed.
Worship in the Orthodox Church is understood to be the highest calling of mankind, to fall down at the feet of the Almighty God, the Holy Trinity, and to be given over entirely to him, becoming united mystically with him in the holy mysteries. To worship God is to fulfil the purpose for which we were created.
Orthodox worship is liturgical, that is, following specific ritual patterns and cycles in reverent dignity and embracing the whole of the human person. Its reverence and awe are due to its being understood as entering into the very throne room of the Creator. Orthodox worship is transformative in its nature, bringing the Christian more deeply into communion with God and with his cooperation changing him into a holy person, a saint.
Worship is distinct from veneration in that the latter is simply the genuine respect that Orthodox Christians show for holy people and things, while worship itself is a total giving over of the self to be united with God.
A secondary but essential component of worship in Orthodoxy is to teach the dogmas of the faith, forming the Christian in the doctrines of the Church.