Gregory was born to Greek parents[10] in the family estate of Karbala outside the village of Arianzus, near Nazianzus, in southwest Cappadocia.

On the way to Athens, his ship encountered a violent storm, and the terrified Gregory prayed to Christ that if He would deliver him, he would dedicate his life to His service.

[6]: 28  While at Athens, he developed a close friendship with his fellow student Basil of Caesarea, and also made the acquaintance of Flavius Claudius Julianus, who would later become the Roman emperor known as Julian.

[13] In 361, Gregory returned to Nazianzus and was ordained a presbyter by his father's wish, who wanted him to assist with caring for local Christians.

[6]: 121  Julian resolved, in late 362, to vigorously prosecute Gregory and his other Christian critics; however, the emperor perished the following year during a campaign against the Persians.

[6]: 143  In the subsequent public debates, presided over by agents of the Emperor Valens, Gregory and Basil emerged triumphant.

[6]: 187–192  Describing his new bishopric, Gregory lamented how it was nothing more than an "utterly dreadful, pokey little hole; a paltry horse-stop on the main road... devoid of water, vegetation, or the company of gentlemen... this was my Church of Sasima!

"[15] He made little effort to administer his new diocese, complaining to Basil that he preferred instead to pursue a contemplative life.

Gregory retorted that he had no intention to continue to play the role of pawn to advance Basil's interests.

Following the deaths of his mother and father in 374, Gregory continued to administer the Diocese of Nazianzus but refused to be named bishop.

Upon the death of Emperor Valens in 378, the accession of Theodosius I, a steadfast supporter of Nicene orthodoxy, was good news to those who wished to purge Constantinople of Arian and Apollinarian domination.

[6]: 235–236 [17] In 379, the Antioch synod and its archbishop, Meletius, asked Gregory to go to Constantinople to lead a theological campaign to win over that city to Nicene orthodoxy.

His cousin Theodosia offered him a villa for his residence; Gregory immediately transformed much of it into a church, naming it Anastasia, "a scene for the resurrection of the faith".

[6]: 241 [18] From this little chapel he delivered five powerful discourses on Nicene doctrine, explaining the nature of the Trinity and the unity of the Godhead.

On the vigil of Easter in 379, an Arian mob burst into his church during worship services, wounding Gregory and killing another bishop.

Maximus I, who was in secret alliance with Peter II of Alexandria, attempted to seize Gregory's position and have himself ordained bishop of Constantinople.

[11]: 43  Shocked, Gregory decided to resign his office, but the faction faithful to him induced him to stay and ejected Maximus I.

This episode left Gregory embarrassed, and exposed him to criticism as a provincial simpleton unable to cope with the intrigues of the imperial city.

[11]: 43 Affairs in Constantinople remained confused as Gregory's position was still unofficial, and Arian priests yet occupied many important churches.

[11]: 45 Theodosius wanted to further unify the entire empire behind the orthodox position and decided to convene a church council to resolve matters of faith and discipline.

Once there, they refused to recognise Gregory's position as head of the church of Constantinople, arguing that his transfer from the See of Sasima was canonically illegitimate.

[20] He shocked the council with his surprise resignation and then delivered a dramatic speech to Theodosius asking to be released from his offices.

[citation needed] Gregory faced stark choices throughout his life: Should he pursue studies as a rhetor or philosopher?

Biographers suggest that it was this dialectic which defined him, forged his character, and inspired his search for meaning and truth.

[23] He emphasized that Jesus did not cease to be God when he became a man, nor did he lose any of his divine attributes when he took on human nature.

[25]: 9–10  The Cappadocian Fathers asserted that God's nature is unknowable to man; helped to develop the framework of hypostases, or three persons united in a single Godhead; illustrated how Jesus is the eikon of the Father; and explained the concept of theosis, the belief that all Christians can be assimilated with God in "imitation of the incarnate Son as the divine model".

[29] Apart from the several theological discourses, Gregory was also one of the most important early Christian men of letters, a very accomplished orator, even perhaps one of the greatest of his time.

[35] During the six years of life which remained to him after his final retirement to his birthplace, Gregory composed the greater part of his copious poetical works.

The poems that he wrote that dealt with his personal affairs refer to the continuous illness and severe sufferings (physical and spiritual) which assailed him during his last years.