Today is the feast of St. Yanah ibn Sarjun, Doctor of the Church, usually known as St. John Damascene. Probably an Arab Christian born in Damascus, his family was associated with the Muslim court. It's unclear whether St. John himself ever actually served in an office in the caliphate, although he might have done so in a minor capacity. It's more likely, however, that his father, Sarjun ibn Mansur, arranged for him to study at the monastery of Mar Saba. In any case, his being a subject of a Muslim empire ironically seems to have made it possible for him to play a key role in the iconoclasm controvery, since he was beyond the reach of the iconoclastic emperors of Constantinople. He also, however, was one of the first Christian critics of Islam who seems to have actually read the Qur'an, rather than having merely to rely on comments by Muslims; he concluded on the basis of it that Islam was a variant of Arianism. We know very little about his life beyond what can be gathered from his writings, but tradition says he died on December 4, 749. From An Exposition of the Orthodox Faith (Book III, Chapter 1):
Man, then, was thus snared by the assault of the arch-fiend, and broke his Creator's command, and was stripped of grace and put off his confidence with God, and covered himself with the asperities of a toilsome life (for this is the meaning of the fig-leaves ); and was clothed about with death, that is, mortality and the grossness of flesh (for this is what the garment of skins signifies); and was banished from Paradise by God's just judgment, and condemned to death, and made subject to corruption. Yet, notwithstanding all this, in His pity, God, Who gave him his being, and Who in His graciousness bestowed on him a life of happiness, did not disregard man. But He first trained him in many ways and called him back, by groans and trembling, by the deluge of water, and the utter destruction of almost the whole race, by confusion and diversity of tongues, by the rule of angels, by the burning of cities, by figurative manifestations of God, by wars and victories and defeats, by signs and wonders, by manifold faculties, by the law and the prophets: for by all these means God earnestly strove to emancipate man from the wide-spread and enslaving bonds of sin, which had made life such a mass of iniquity, and to effect man's return to a life of happiness. For it was sin that brought death like a wild and savage beast into the world to the ruin of the human life. But it behooved the Redeemer to be without sin, and not made liable through sin to death, and further, that His nature should be strengthened and renewed, and trained by labour and taught the way of virtue which leads away from corruption to the life eternal and, in the end, is revealed the mighty ocean of love to man that is about Him. For the very Creator and Lord Himself undertakes a struggle in behalf of the work of His own hands, and learns by toil to become Master.