A polemical writer against Christianity, Celsus flourished towards the end of the second century. Very little is known about his personal history except that he lived during the reign of Marcus Aurelius, that his literary activity falls between the years 175 to 180, and that he wrote his The True Word against the Christian religion. He is one of several writers named “Celsus” who appeared as opponents of Christianity in the second century; he is probably the Celsus who was known as a friend of Lucian. Some doubt this identification, however, because Origen writes that Lucian’s friend was a follower of Epicurus, and the author of The True Word shows himself to follow Plato and perhaps Philo. It is generally supposed that Celsus was a Greek or Roman. However, his acquaintance with Judaism and his knowledge of Egyptian ideas and customs incline some historians to think he belonged to the Eastern portion of the empire. Those who believe him to have been a Roman explain his knowledge of Jewish and Egyptian matters by assuming that he acquired that knowledge either by travelling, or by mingling with the foreign population of Rome. Celsus wrote his work The True Word as a polemic against the Christians in approximately AD 178, or generally between AD 170 and 180. Celsus divided the work into two sections, the one in which objections are put in the mouth of a Jewish interlocutor and the other in which Celsus speaks as the pagan philosopher that he is.
Celsus ridiculed Christians for what he perceived to be an advocacy of faith instead of reason. About 60 years after it was first published, the book written by Celsus inspired a massive refutation by Origen in Contra Celsum, which is our source of knowledge for Celsus, who was later condemned along with other critics such as Porphyry. In 248, although the Church was under no widespread persecution, owing to the inertia or implicit toleration of the emperor Philip the Arab, the atmosphere was full of conflict. Rome was celebrating the 1000th anniversary of its founding, and imperial aspirations and ideas were naturally prominent. The state and the worship of the Caesar, however, were contrasted by Origen with the Christian ideal of a rule and a citizenship beyond this world, to which a thousand years were but as a day. Pride in his faith was blended with a natural anxiety stemming from Celsus’ attacks on Christianity, and it was at this point that Origen brought to light again a book written in the days of Marcus Aurelius. Sometimes quoting, sometimes paraphrasing, sometimes merely referring, Origen reproduces and replies to all Celsus’ arguments. His work shows many signs of haste, but he more than compensates for this by the way in which he thus preserves a singularly interesting memorial of the 2nd century: only about one-tenth of The True Word is really lost, and about three-quarters of what we have is verbatim text, quoted by Origen. Celsus opens the way for his own attack by restating the arguments leveled at the Christians by the Jews. They are: Jesus was born in adultery and nurtured on the wisdom of Egypt. His assertion of divine dignity is disproved by his poverty and his miserable end. Christians have no standing in the Old Testament prophecies and their talk of a resurrection that was only revealed to some of their own adherents is foolishness. Celsus indeed says that the Jews are almost as ridiculous as the foes they attack; the latter said the savior from Heaven had come, the former still looked for his coming. However, the Jews have the advantage of being an ancient nation with an ancient faith.
The idea of an incarnation of God is absurd; why should the human race think itself so superior to bees, ants and elephants as to be put in this unique relation to its maker? And why should God choose to come to men as a Jew? The Christian idea of a special providence is nonsense, an insult to the deity. Christians are like a council of frogs in a marsh or a synod of worms on a dunghill, croaking and squeaking, “For our sakes was the world created.” To him, it was much more reasonable to believe that each part of the world has its own special deity; prophets and supernatural messengers had appeared in more places than one. Besides being bad philosophy based on fictitious history, Christianity is not respectable. Celsus does not indeed repeat the Thyestean charges so frequently brought against Christians, but he says the Christian teachers who are mainly weavers and cobblers have no power over men of education. The qualifications for conversion are ignorance and childish timidity. He writes: “Like all quacks they gather a crowd of slaves, children, women and idlers.