The Orthodox Church beliefs are captured in the Nicene Creed, adopted by the First Ecumenical Council of Nicaea, in 325. It is recited in each liturgy and is as follows:
I believe in one God, Father Almighty, maker of heaven and earth, of all things visible and invisible.
And in one Lord Jesus Christ, the Only Begotten Son of God, begotten of the Father before all ages. Light of Light, true God of true God, begotten, not created, of one essence with the Father; through whom all things were made.
Who for us men and our salvation, came down from heaven, and was incarnate by the Holy Spirit and the Virgin Mary, and became man.
He was crucified for us under Pontius Pilate; he suffered and was buried. He rose on the third day, according to the Scriptures. He ascended into heaven and is seated at the right hand of the Father.
He will come again in glory to judge the living and the dead and his kingdom shall have no end.
I believe in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father, who together with the Father and the Son is worshipped and glorified, who spoke through the prophets.
I believe in one, holy, catholic and apostolic Church. I acknowledge one Baptism for the forgiveness of sins and I look for the resurrection of the dead and the life of the age to come. Amen.