Gregory of Nyssa
Gregory was the son of two other people listed as saints. Basil and Emmilia but Gregory was raised by his older brother identified as Saint Basil the Great, and his sister, Macrina.
This took place in what is modern-day Turkey.
Gregory was very intelligent and became a professor of rhetoric but would devote his learning and efforts to the Church activities. He was married and became ordained since no one had made rules about celibacy for priests yet.
He became Bishop of Nyssa in 372 during the time of the Arian heresy, which supposedly denied the divinity of Christ.
He was arrested on charges of embezzling Church funds, but was restored to his See in 378.
Gregory wrote with great effectiveness against Arianism and other doctrines, gaining a reputation as a defender of certain other doctrines of men labeled orthodoxy.
He held a position of prominence at the Council of Constantinople to censor heresies. He is seen by some to be a "pillar of orthodoxy" as a supporter of some of the mystical tradition in Christian and monasticism.
Gregory of Nyssa mentioned:
Origen suggestion that the Zechariah mentioned in Matthew 23:35 may be the father of John the Baptist includes "The latter view is that of Origen, Basil, Gregory of Nyssa, Theophylact, and several others among the Fathers (see Thilo, Praef. p. lxiv. f.); and recently of Müller in the Stud. u. Krit. 1841, p. 673 ff." Meyer's New Testament Commentary
Summa Theologiae, by Thomas Aquinas, Article VI, Objection 1. "It would seem that all things are governed by God immediately. For Gregory of Nyssa (Nemesius, De Nat. Hom.) reproves the opinion of Plato who divides providence into three parts. The first he ascribes to the supreme god, who watches over heavenly things and all universals; the second providence he attributes to the secondary deities, who go the round of the heavens to watch over generation and corruption; while he ascribes a third providence to certain spirits who are guardians on earth of human actions. Therefore it seems that all things are immediately governed by God."