Gregory was raised in present-day Turkey by his older brother, St. Basil the Great, and his sister, Macrina. He was the son of two saints, Basil and Emmilia. Gregory's academic achievements indicated that he had a bright future. After being appointed a professor of rhetoric, he was convinced to focus his education and efforts on the Church. Gregory was already married, but since celibacy was not yet a legal requirement for priests, he continued his studies and eventually received his ordination.

In 372—during a time of intense tension due to the Arian heresy, which rejected Christ's divinity—he was chosen Bishop of Nyssa (in Lower Armenia). Gregory's return to his see in 378, following a brief detention on a false charge of embezzling Church funds, was warmly received by his people.

Gregory truly came into his own following the passing of his adored brother, Basil. He established a reputation as an orthodoxy defender by writing persuasively against Arianism and other dubious views. He held a prominent role at the Council of Constantinople and was dispatched on missions to combat various heresies. For the rest of his life, he maintained his excellent reputation, but as the authorship of his works became increasingly uncertain over the ages, it progressively deteriorated. However, his stature is once again recognized because of the efforts of scholars in the 20th century. Indeed, St. Gregory of Nyssa is regarded as one of the major contributions to the mystical tradition in Christian spirituality and monasticism itself, rather than just a pillar of orthodoxy.

Other Saints of the Day
St. Dermot
St. Saethryth
St. Peter Urseolus
St. William of Bourges
St. John Camillus the Good