Orthodoxy and Heterodoxy
by Fr. V. Potapov

• What is Orthodoxy?
• Western Theology
• Western Church and Culture of Rome
• Great Schism of 1054
• Filioque
• Veneration of the Mother of God
• Original Sin
• Supererogatory Works
• Purgatory and Indulgences
• Primacy and "Infallibility" of the Roman Pope
• Roman Catholic Theory on the Development of Dogma and the Problem of Ecclesiastical Authority
• Differences in the Sacraments 
• Spirituality of the Christian West and the Orthodox East
• The Orthodox in the Eyes of the Vatican
• Protestantism
• Ecumenism

Other Readings

• Difference Between Orthodoxy and Western Confessions, Metropolitan Anthony 
• Sola Scriptura?  How Orthodox and Protestant understandings of the Scriptures differ, by John Whiteford
• How Orthodox teaching on salvation differs from that of the Protestants, by Paul Jacobson

Irenaeus (2nd Century)

•    On the Uniform Teaching of the Church
•    Truth is to be found nowhere else but in the Church
•    Many questions must be left in the Hands of God