At first he studied in Caesarea of Palestine, then in Alexandria, and finally in Athens. As he was sailing from Alexandria to Athens, a violent sea storm put in peril not only his life but also his salvation, since he had not yet been [[baptism|baptized]]. With tears and fervour he besought God to spare him, vowing to dedicate his whole self to Him, and the tempest gave way to calm. At Athens Saint Gregory was later joined by St. [[Basil the Great]], whom he already knew; but now their acquaintanceship grew into a lifelong brotherly love. Another fellow student of theirs in Athens was the young Prince Julian, who later as Emperor was called the [[Apostate]] because he denied Christ and did all in his power to restore paganism. Even in Athens, before Julian had thrown off the mask of piety; St. Gregory saw what an unsettled mind he had, and said, "What an evil the Roman State is nourishing" (Orat. V, 24, PG 35:693).

About the year 379, Saint Gregory came to the assistance of the [[Church of Constantinople]], which had already been troubled for forty years by the [[Arianism|Arians]]; by his supremely wise words and many labours he freed it from the corruption of [[heresy]], and was elected Archbishop of that city by the [[Second Ecumenical Council]], which assembled there in 381, and condemned Macedonius, Archbishop of Constantinople, as the enemy of the [[Holy Spirit]]. When St. Gregory came to Constantinople, the Arians had taken all the churches and he was forced to serve in a house chapel dedicated to St. Anastasia the [[Martyr]]. From there he began to preach his famous five [[sermon]]s on the [[Trinity]], called the ''Triadica''. When he left Constantinople two years later, the Arians did not have one church left to them in the city. St. Meletius of Antioch (see [[February 12|Feb. 12]]), who was presiding over the Second Ecumenical Council, died in the course of it, and St. Gregory was chosen in his stead; there he distinguished himself in his expositions of dogmatic theology.