For my Early Christian Thought class, we've been assigned to read "An Answer to Ablabius: That We Should Not Think of Saying There Are Three Gods" by Gregory of Nyssa. This little section included in volume III of Christology of the Later Fathers has been particularly helpful to read. Gregory wrote this brilliant work in order to answer the charges of tritheism. At the end of the introduction, the translator writes the following:
“It would be difficult to find a Church father who so admirably expresses the full round of Eastern Orthodox teaching: its clear Trinitarianism, its mysticism, its asceticism, its realistic sacramentalism, its ideal of man’s deification, and its blending of Platonic and Aristotelian forms of thought. In Gregory, too, is to be seen the weakness sometimes apparent in Eastern theology: its failure to grasp the meaning of history and its difficulty in freeing itself fully from Hellenic elements in its approach to creation, sexuality, and death” (p. 250).
Among other reasons, I wonder if this is partly why Barth never found Eastern Orthodoxy fully convincing? Just a small observation.