St. Gregory of Nyssa was the brother of St. Basil the Great and at first a married priest. After his wife died, he was then consecrated by St. Basil as Bishop of Nyssa in a.d. 372. Nyssa is in Cappadocia, now in present day Turkey, and near St. Basil’s episcopal see in Caesarea. St. Gregory is called one of the Cappa-docian Fathers, along with St. Basil the Great and St. Gregory of Nazianzus, whose influence on Christian theology has been profound. He is shown in this icon in episcopal vesture.
St. Gregory had a strong effect on Trinitarian doctrine, teaching that in all things these Three Persons of the Trinity act together and in harmony of will and action, although still maintaining Their uniqueness of Person and function. St. Gregory also emphasized that God is infinite, which had not been taught as such very much before him. To know God, therefore, involves entering into a transcendent knowledge without preconceived notions. His major work, The Life of Moses, marks him as a leader in Apophatic theology. St. Gregory was present at the Second Ecumenical Council in a.d. 381, and died in 394 at 59 years old.