Gregory of Nyssa was a fourth-century bishop and theologian of Cappadocia in Asia Minor, the younger brother of Saint Basil the Great and one of the three Cappadocian Fathers, alongside Basil and Gregory the Theologian. Born around 335 into a family that produced several saints, he became one of the most influential and speculative theologians of the early Church, and is commemorated by the Orthodox Church on January 10.
Unlike his siblings, Gregory did not at first embrace the ascetic life. After receiving baptism and serving as a lector, he was drawn to classical learning, devoting himself to the study of rhetoric and to teaching, and he entered into marriage. By tradition, the death of his wife marked a turning point, and, encouraged by his brother Basil and his friend Gregory of Nazianzus, he withdrew from worldly pursuits and spent a period of retreat at the monastery Basil had founded by the river Iris.
In 372 Gregory was consecrated bishop of Nyssa in Cappadocia by his brother Basil, who was then metropolitan of Caesarea. His episcopate fell during the height of the Arian controversy. Falsely accused by his opponents of misusing church property, he was deposed and exiled during the reign of the Arian-supporting emperor Valens; a synod of Arian bishops also deposed him in absentia. After Valens died in 378 Gregory was restored to his see and welcomed back by his people.
Following the death of Basil in 379, Gregory emerged as a leading defender of the Nicene faith. He became one of the chief figures of the Second Ecumenical Council, held at Constantinople in 381 against the Macedonian (Pneumatomachian) teaching that denied the full divinity of the Holy Spirit, and he took a key part in completing the Nicene-Constantinopolitan Creed. He died in old age not long after the Council, leaving an extensive body of dogmatic, ascetic, and exegetical writings, and is honored as one of the most profound Christian thinkers of his age.
