[1] John became a monk, and later priest, at the Monastery of St Zacchaeus, near the city of Raqqa in Syria.
[1] John's twenty-second canon forbade the adoption of pagan funeral customs and his twenty-third canon forbade adherents who had married their daughters to pagans, Jews, and Zoroastrians from entering the church.
[1] He later consecrated a certain David, a monk of the Monastery of Qartmin, as Bishop of Harran.
[3] In 869, John held the Council of Capharthutha and issued eight canons on the offices of patriarch and maphrian.
A total of eighty-six bishops were ordained by John during his tenure and he served in the office of patriarch until his death on 3 January 873.