Saint Gregory of Nyssa was born into a deeply devout Christian family. His mother, Emmelia, was the daughter of a martyr. Two of his brothers, Saint Basil of Caesarea and Saint Peter of Sebaste, later became bishops, as did Gregory himself. His eldest sister, Saint Macrina the Younger, was renowned for her holiness and became a lasting example of Christian piety.
It appears that Saint Gregory was married for a time. A letter written to him by Saint Gregory of Nazianzus consoles him on the death of a woman named Theosebeia, who is widely believed to have been his wife. She too is venerated as a Saint in the Orthodox tradition.
According to Saint Gregory of Nazianzus, it was Saint Basil of Caesarea who consecrated Saint Gregory as Bishop of Nyssa around the year 371.
Saint Gregory’s episcopal ministry was marked by serious trials. Demosthenes, the Governor of Pontus, ordered his arrest, and a synod held at Nyssa unjustly deposed him. Forced into exile, he wandered from place to place until the death of Emperor Valens in 378. With the accession of Emperor Gratian, an edict of tolerance was issued, allowing Saint Gregory to return to his diocese, where he was welcomed back with great joy.
In 379, Saint Gregory took part in the Council of Antioch, convened to address the Meletian schism. He firmly upheld the faith of Nicaea and worked tirelessly to oppose Arianism and Pneumatism in the Eastern Church. It is also very likely that he was present at the Council of Constantinople in 383.
Between the years 385 and 386, Saint Gregory of Nyssa disappears from the historical record. Nevertheless, he left behind a rich legacy of theological writings. Through these works, he made profound and lasting contributions to the Church’s understanding of the Holy Trinity and played a key role in the development and defense of the Nicene Creed.