In the year 717, when Armenia was under the yoke of Arab conquerors, St. John of Odzun, inherited the throne of Catholicos of Armenia and began to preach the true faith. It is known that during festivities he presented himself in luxurious vestments, sprinkling his thick, wavy beard with a mixture of rose water and golden pollen. The majestic appearance of the Armenian bishop was the subject of both admiration and envy, even for Arabs. When the rumour about John reached the Caliph himself, he invited the righteous to his residence and inquired about why the Armenian Patriarch’s vestments were so luxurious as opposed to poor garments of Christ and His disciples. The saint replied that he did not possess the inner beauty and strength of the founder of Christianity and His disciples, so was forced to decorate at least his appearance in order to appear respectable in the eyes of the people. At the same time he showed to his inquisitor the hair-shirt he was wearing under his rich vestments which tormented his naked body. Seeing this, the Caliph inadvertently developed great awe and reverence toward his guest and, bowing before him, asked for blessing.
During his reign as the Catholicos and Supreme Patriarch, St. John convened ecumenical councils in Dvin and Manazkert (Manzikert) to discuss doctrinal and other important matters of the Church. He authored the first Armenian book of canons along with many theological works, wrote sermons and sharakans (hymns). He was also called John the Philosopher.
In the last years of his life, passing the patriarchal throne to his successor, the saint retired to the desert, not far from his hometown, where he remained a hermit monk until his death.