Orthodox theology is the study of God from the perspective of Orthodox Christian scholars. Also known as Greek and Eastern Orthodox, the Orthodox Church is the Eastern European and Middle Eastern branch of Christianity. There are a number of theological differences between Orthodox and Catholic theology. On the face of it, many seem like small differences of opinion, but over the centuries, these differences have led to schisms and breakdowns between the two churches. These differences include the nature of God, the nature of Christ, the Eucharist and man’s salvation.
Orthodox theology is as old as Christian theology. Many of the principles still adhered to by Orthodox Christians — for example, the nature of Christ — are the same as the first Christians. It also covers, geographically, the area where Christianity was born. It centers around the Greek East Mediterranean, which was originally the Eastern Roman Empire centered on Constantinople. Its power and influence waned as territories were lost, first to the Persian Empire, then to the Muslim Caliphate and, finally, the Ottoman Turks. Orthodox theology is still studied in Christian communities in Greece, parts of the Balkans, Eastern European countries such as Russia and in small communities in the Middle East.
Orthodox theology holds that God, Christ and the Holy Spirit are three separate beings, but that they share the same common essence. The theology also holds to the original Greek draft of the Nicene Creed that stated the Holy Spirit came from God. The Latin text, however, stated that the Holy Spirit came from God and Christ, in an addition known as the Filioque. This difference, as well as the nature of the trinity, led to the schism of 1054.
As Christ and God share the same essence, the nature of Christ is an important part of Orthodox theology. To Orthodox Christians, Christ is 100-percent human and 100-percent God. They believe in the Christ that lived, that sacrificed himself for mankind and who was resurrected on the third day.
In terms of the Eucharist, Orthodox theology agrees with Catholic theology in that the bread and the wine literally turn in to the body and blood of Christ during transubstantiation. They, however, disagree over the type of bread used. Orthodox theology holds that leavened bread, bread made with yeast, must be used so the leavening effect represents the Holy Spirit.
Another important part of Orthodox theology is the idea of salvation. Orthodox theology did not adopt the ideas of Augustine of Hippo, so it maintains the earlier belief that Christ died in order to restore mankind’s place in the world to the same level as before the fall of Adam and Eve. Orthodox theologians believe that God is merciful and grants salvation to those who will accept it and who work with God to achieve it.