Against Celsus 8.61

Consider for yourself, then, what kind of character the God over all will accept rather, he who is able, as no one else is, to do everything, including benefiting men in soul, body, or external things: the one devoted to him in everything, or the one who busies himself with the names of demons, their powers and actions, incantations, herbs proper to demons, and stones with engravings on them corresponding to the forms of demons handed down, whether symbolic or of whatever kind. It is clear to anyone who can follow even a little that the unaffected character, free from such meddling and for that reason devoted to God over all, will be acceptable to God and to all who are akin to him; while the character that, for the sake of bodily health and love of the body and good fortune in indifferent things, busies itself with the names of demons and seeks how to charm the demons with certain incantations, God will leave, as wicked, impious, and more demonic than human, to those whom the one who says such things to demons has chosen, to be torn apart by the thoughts each of them suggests, or by other evils too. For it is likely that, being wicked and, as Celsus admitted, riveted to blood and the savour of fat and melodies and other such things, they do not keep faith and, as it were, pledges even toward those who gratify them with these things. For if others call on them against those who have served them, and buy their service with more blood and savour of fat and the service they need, they might plot against the one who served them yesterday and gave them a share of the feast they love.