As a young man he became a monk in the Studite Monastery in Constantinople; later he bacame abbot of the Monastery of St Mamas, also in Constantinople. After a life of great asceticism, including many trials, criticisms and afflictions, he reposed in peace. (He reposed on March 12, but since this day always falls during the Great Fast, his feast is kept today.) His teaching on the soul's ability to enter directly into communion with God in this life aroused some opposition in his own time, and the title 'New Theologian' was not always applied in a positive sense. His experiential, mystical teachings are firmly rooted in his doctrine of the Church: his writings contain many powerful affirmations of the centrality of participation in the Mysteries in our struggle for salvation. He is the author of many sublimely beautiful sermons, writings and hymns, a number of them in metered verse. With St John the Evangelist and St Gregory, Patriarch of Constantinople, he is one of only three whom the Church has officially called "Theologian."