Cappadocian fathers, Basil and the two Gregorys, helped bring about the final form of the Nicene Creed in 381 at the Council of Constantinople by suggesting the distinction between ousia (substance) which is one in God and hypostasis (subsistence, person) which is three in God. Thus, the Nicene faith is often summed up as belief that God is one substance and three persons. Or, expressed more informally, it might be said that God is one “what” and three “whos.”
