Justin Martyr (ca. 100–ca. 165 CE) was an early defender of the Christian religion who was put to death for his faith. At a time when pagans regarded Christianity as an irrational superstition, Justin argued that polytheism was nothing more than an empty façade erected by demons to deceive humankind and hinder the saving message of Christ. The Hebrew scriptures had foretold this in no uncertain terms: “They sacrificed to devils and not to God, to gods whom they knew not” (Deuteronomy 32:17). In a letter written in defense of Christianity to the Roman Senate sometime between 155 and 160 CE, Justin explained that demons in the guise of gods had enslaved the human race by means of magic, war, and immoral behavior. Appropriating the story of the Watchers from Jewish apocryphal traditions to explain the origin of demonkind, Justin described how these evil spirits masqueraded as gods and used their fraudulent authority to compel Roman magistrates to persecute innocent Christians.
When God made the whole world and subjected earthly things to humankind and arranged the heavenly bodies for the increase of fruits and the rotation of the seasons, and appointed all of this by divine law…He also committed the care of humankind and of all things under heaven to his angels, whom He appointed over them. But the angels violated their responsibilities because they were captivated by the love of women and had children with them who are called demons. Moreover, the fallen angels and their offspring afterwards subdued the human race to themselves, partly by means of magical writings, partly by fears they instilled in them and punishments they inflicted on them, and partly by teaching them to offer sacrifices and incense and libations, which the fallen angels needed after they were enslaved by lustful passions. And among humankind they sowed murders, wars, adulteries, discord, and all manner of wickedness. Thus it was that the poets and writers of legends, not knowing that it was the fallen angels and those demons who had been produced by them that did these things to men and women and cities and nations, ascribed them to Jupiter himself and to those whom they thought were his children and to the children of those who were called his brothers—Neptune and Pluto—and to the children of their children. For they called them by whatever name each of the fallen angels had given to himself and his children.