St Theodosius was born at Garissus, incorrectly called Mogarissus, in Cappadocia in 423. He was moved by Abraham’s example in quitting his country and friends, he undertook a pilgrimage to Jerusalem. There he visited the famed St Simeon Stylites who foretold many circumstances of his future life, and gave him his advice and instruction regarding them. Having satisfied his devotion in visiting the holy places in Jerusalem, he began to consider in what manner he should dedicate himself to God. The dangers of living without a guide made him prefer a monastery to a hermitage; and he therefore put himself under the direction of a holy man named Longinus, who soon conceived a warm affection for his disciple. Thereafter he retired to a cave at the top of a neighboring mountain.
When many sought to serve God under his direction Theodosius at first determined only to admit six or seven, but was soon obliged to receive a greater number, and at length came to a resolution never to reject any that presented themselves with dispositions that seemed sincere. When the holy company of disciples was twelve in number, it happened that at Easter they had nothing to eat— they had not even bread for the sacrifice. Some murmured, but the saint bade them trust in God and He would provide: which was soon remarkably verified by the arrival of a train of mules loaded with provisions. The sanctity and miracles of St Theodosius attracting numbers who desired to serve God under his direction, the available space proved too small for their reception. Accordingly he built a spacious monastery at a place called Cathismus, not far from Bethlehem, and it was soon filled with monks.
The monastery itself was like a city of saints in the midst of a desert, and in it reigned regularity, silence, charity and peace. The monks passed a considerable part of the day and night in the church, and at the times not set apart for public prayer and necessary rest, everyone was obliged to apply himself to some trade or manual labor not incompatible with recollection, in order that the house might be supplied with conveniences. Sallust, Patriarch of Jerusalem, appointed St Sabas head of all the hermits, and our saint of the cenobites, or men living in community, throughout Palestine, whence he was styled “the Cenobiarch.” These two great servants of God lived in close friendship, and it was not long before they were also united in their sufferings for the Church.
The Emperor Anastasius (491-518) patronized the Eutychian heresy, and used all possible means to win our saint over to his own views and gave him a considerable sum of money. Theodosius distributed all this money among the poor and on coming to know of this, the emperor sent an order for his banishment, which was executed; but dying soon after; Theodosius was recalled by his successor, Justin.
During the last year of his life St Theodosius was afflicted with a painful infirmity, in which he gave proof of heroic patience and submission to the will of God; for being advised by a witness of his sufferings to pray that God would grant him some ease, he would give no ear to the suggestion, alleging that such ideas implied a lack of patience. Perceiving that his end was close at hand, he addressed a last exhortation to his disciples, and foretold many things which came to pass after his death. He went to his reward in 529, in the one hundred and fifth year of his age. Peter, Patriarch of Jerusalem, and the whole country were present at his funeral, which was honored by miracles. He was buried in his first cell, called the cave of the Magi, because the wise men who came to find Christ soon after his birth were said to have lodged in it.