The Holy Martyr Barbarus, formerly a robber, lived in Greece and for a long time he committed robberies, extortions and murders. But the Lord, Who does not desire the death of a sinner, turned him to repentance. Once, when Barbarus was sitting in a cave and gazing upon his stolen possessions, the grace of God touched his heart. He thought about the inevitability of death, and about the dread Last Judgment. Pondering over the multitude of his wicked deeds, he was distressed in his heart and he decided to make a beginning of repentance, saying, "The Lord did not despise the prayer of the robber hanging beside Him. May He spare me through His ineffable mercy."
Barbarus left all his treasures behind in the cave and he went to the nearest church. He did not conceal his wicked deeds from the priest, and he asked to be accepted for repentance. The priest gave him a place in his own home, and St Barbarus followed him, going about on his hands and knees like a four-legged animal, since he considered himself unworthy to be called a man. In the household of the priest he lived with the cattle, eating with the animals and considering himself more wicked than any creature. Having received absolution from his sins from the priest, Barbarus went into the woods and lived there for twelve years, naked and without clothing, suffering from the cold and heat. His body became dirty and blackened all over.
Finally, St Barbarus received a sign from on high that his sins were forgiven, and that he would die a martyr's death. Once, merchants came to the place where St Barbarus labored. In the deep grass before them they saw something moving. Thinking that this was an animal, they shot several arrows from their bows. Coming closer, they were terrified to see that they had mortally wounded a man. St Barbarus begged them not to grieve. He told them about himself and he asked that they relate what had happened to the priest at whose house he had once lived.
After this, St Barbarus yielded up his spirit to God. The priest, who had accepted the repentance of the former robber, found his body shining with a heavenly light. The priest buried the body of St Barbarus at the place where he was killed. Afterwards, a curative myrrh began to issue forth from the grave of the saint, which healed various maladies. His relics are located at the monastery of Kellios in Thessaly, near the city of Larissa.