The Orthodox stream of Christianity developed from the church’s spread across the eastern Roman, or Byzantine, Empire in the first few centuries after Jesus.
In addition to the key beliefs common to all Christians, Orthodox Christians believe: Holy Tradition is an important and distinct source of faith. It describes how the Holy Spirit infuses the life of the church, providing continuity and unity among the faithful; Holy icons (consecrated pictures) are important elements in both public and private devotion; hat saints, created through the process of canonisation, can intercede with God on behalf of people who are alive and petition for their memory.
Orthodox Christians do not believe in the Catholic teaching of the eucharist or of the immaculate conception of Mary. The Virgin Mary is honoured as theotokos (Mother of God).
From Christianity - Orthodox, ABC, accessed 16/04/2016, <http://www.abc.net.au/religion/stories/s817554.htm>