What does the Orthodox Christian Church believe?

Answer 1

The Creed (meaning: I believe) or The Symbol of Faith

I believe in one God , the Father, Almighty, the Maker of Heaven and earth, and of all things visible and invisible.
And in one Lord Jesus Christ, the Son of God, the Only Begotten, begotten of the Father before all ages, Light from Light, True God of True God, begotten not made of One Essence with the Father through Whom all things were made:
Who for us men and for our salvation came down from Heaven, and was incarnate by the Holy Spirit and the Virgin Mary, and became Man;
And was crucified for us under Pontius Pilate, and suffered and was buried:
And He rose again on th! e third day, according to the Scriptures;
And ascended into Heaven, and sitteth at the right hand of the Father:
And He will come again with glory to judge the living and the dead;
And His kingdom will have no end:
And in the Holy Spirit, the Lord, the Giver of Life, Who proceedeth from the Father, Who with the Father and the Son is equally worshipped and glorified, Who spoke by the Prophets:
And in One, Holy, Catholic, and Apostolic Church.
I confess on Baptism for the remission of sins.
I look for the Resurrection of the Dead;
And the life of the age to come.
Amen

Notice that we do not use the filioque. That was an innovation by heretics in Spain initially, I believe. It was NOT added by the Church. It was forced on the Roman Pope by the king.