Saint Theoctiste was born in the city of Methymna on the island of Lesbos. At an early age she was left a complete orphan, and relatives sent her to a monastery to be raised. The girl was happy to be removed from the world of sin, and she liked the monastic life, the long church services, monastic obedience, the strict fasting and unceasing prayer. She learned much of the singing, prayer and psalmody by heart.
In the year 846 when she was already eighteen years old, she set off with the blessing of the abbess, on the Feast of the Resurrection of Christ, to a neighboring village to visit her sister and she remained there overnight. Arabs invaded the settlement, and they took captive all the inhabitants, loaded them on a ship, and by morning they were at sea.
The brigands took the captives to the desolate island of Paros so that they might examine them in order to assign a value to each when they were sold at the slave-market. The Lord helped the young maiden to flee, and the Arabs did not catch her. From that time St Theoctiste dwelt on the island for 35 years. An old church in the name of the Most Holy Theotokos served as her dwelling, and her food was sunflower seeds. All her time was spent in prayer.
Once, a group of hunters landed upon the island. One of them, pursuing his prey, went far off from the coast into the forest and suddenly he saw the church. He went into the church so as to offer up a prayer to the Lord. After the prayer the hunter saw what looked like a human form in a dim corner, not far from the holy altar table, through thick cobwebs. He went closer and heard a voice, "Stay there, fellow, and come no closer to shame me, since I am a naked woman." The hunter gave the woman his outer clothing and she came out from concealment. He beheld a grey-haired woman with worn face, calling herself Theoctiste. With a weak voice she told of her life fully devoted to God.
When she finished her story, the saint asked the hunter, if he happened to come to this island again, that he should bring her a particle of the Presanctified Gifts. During all her time of living in the wilderness she not once was granted to partake of the Holy Mysteries of Christ.
A year later, the hunter again arrived upon the island and brought a small vessel with a particle of the Holy Mysteries. St Theoctiste met the Holy Gifts in the church, fell down to the ground and prayed long with tears. Standing up, she took the vessel and with reverence and in the fear of God she received the Body and Blood of Christ.
On the following day the hunter saw the dead body of the nun Theoctiste in the church. After digging a shallow grave, the hunter placed the venerable body of the nun in it. As he did so, he impudently cut off her hand, so as to take with him part of the relics of the great saint of God. All night the ship sailed upon a tempestuous sea, and in the morning it found itself at the very place from which it began. The man then perceived that taking the relic was not pleasing to God.
He returned to the grave and placed the hand with the body of the saint. After this the ship sailed off unhindered. On the journey the hunter told his companions everything that had happened on the island. Listening to him, they all decided immediately to return to Paros, to venerate the relics of the great ascetic, but they could not find her holy body in the grave.