Saint John (Saakadze) of Manglisi was born in 1668 and spiritually nurtured in the Davit-Gareji Wilderness. Outstanding in virtue, John was quickly ordained a hieromonk, and soon after consecrated bishop of Manglisi.
In 1724 Saint John left Davit-Gareji for Derbend, Dagestan, where he constructed a wooden church and began to preach Christianity among the local people. He labored there with eleven other pious believers. Saint John’s humble life and the miracles he performed attracted the attention of the Muslim Dagestanis, and even the government took notice of his tireless evangelical activity.
At that time the Georgian King Vakhtang VI (1703-1724) and Tsar Peter the Great of Russia were corresponding regularly about the evangelization of the Caspian seacoast. Both kings recognized the importance of Saint John’s activity in regard to this matter, and they generously contributed to his efforts. With their help, Saint John built one church in honor of the Nativity of the Theotokos and another in honor of Great-martyr Catherine.
In 1737 John left his disciples in Dagestan and journeyed to Astrakhan, near the place where the Volga flows into the Caspian Sea. There he constructed a church in honor of Saint John the Evangelist, which was converted into a monastery in 1746. Archimandrite Herman, one of Saint John’s disciples, was elevated as abbot of this monastery.
While in Astrakhan, Saint John discovered that many ethnic Georgians were passing through the city of Kizliar in Ossetia, but they did not have a church in which to celebrate the divine services. So he traveled to Kizliar and, with help from his kinsmen, built a church and opened a preparatory school for clergy nearby.
On March 28, 1751, Saint John reposed in Kizliar at the age of eighty. He was buried in the church that he himself had constructed.
Later, by order of King Teimuraz II (1744-1761), the myrrh-streaming relics of Saint John were translated to Tbilisi and buried in Sioni Cathedral, in front of the Manglisi Icon of the Mother of God.