There is quite a lot, not what I would consider to be easy reading but thought-provoking nonetheless: - Byzantine Theology is a good overview of many of the co

There is quite a lot, not what I would consider to be easy reading but thought-provoking nonetheless: - Byzantine Theology is a good overview of many of the concepts that differentiate the East from the West (https://www.amazon.com/Byzantine-Theology-Historical-Trends-Doctrinal/dp/0823209679/ https://www.amazon.com/Byzantine-Theology-Historical-Trends-...) - Divine Essence and Divine Energies (a critical distinction that has been lost in the West) (https://www.amazon.com/Divine-Essence-Energies-Ecumenical-Reflections/dp/0227173864/ https://www.amazon.com/Divine-Essence-Energies-Ecumenical-Re...) - Any of the works by St. Maximus the Confessor Lots more...