St. Gregory the Theologian (329-390)

Archbishop of Constantinople and one of the Three Holy Hierarchs, and one of only three saints the Church calls the Theologian, with St John the Evangelist and St Symeon. In 380, preaching in a small chapel in a city whose churches were all held by the Arians, he gave the five Theological Orations that settled how the Church speaks of the Trinity: one God because one Father, the Son begotten, the Spirit proceeding, three Persons in one nature. Against those who gave Christ a divine mind in place of a human one he answered with the principle every later Christology depends on: what has not been assumed has not been healed. He presided for a time over the Second Ecumenical Council and resigned his see rather than be the cause of a quarrel, went home to Nazianzus and wrote poetry. Feast: January 25.