1 Corinthians 10:20

So what am I saying, that something is sacrificed to an idol? Not that an idol is something; but those who sacrifice, sacrifice to demons. An idol is truly nothing; because an image appears of a dead thing: but under the cover of idols the …

But abstain from things offered to idols; [1 Corinthians 10:20] for they offer them in honour of demons, that is, to the dishonour of the one God, that you may not become partners with demons.

"For that which the Gentiles sacrifice," saith he, "they sacrifice to demons, and not to God." Do not then run to the contrary things. For neither if thou wert a king's son, and having the privilege of thy father's table, shouldest leave it and choose to partake of the table of the condemned and the prisoners in the dungeon, would thy father permit it, but with great vehemence he would withdraw thee; not as though the table could harm thee, but because it disgraces thy nobility and the royal table. For verily these too are servants who have offended; dishonored, condemned, prisoners reserved for intolerable punishment, accountable for ten thousand crimes. How then art thou not ashamed to imitate the gluttonous and vulgar crew, in that when these condemned persons set out a table, thou runnest thither and partakest of the viands? Here is the cause why I seek to withdraw thee. For the intention of the sacrificers, and the person of the receivers, maketh the things set before thee unclean. "And I would not that ye should have communion with demons." Perceivest thou the kindness of a careful father? Perceivest thou also the very word, what force it hath to express his feeling? "For it is my wish," saith he, "that you have nothing in common with them."

For as the bread and wine of the Eucharist before the holy invocation of the adorable Trinity were ordinary bread and wine, while after the invocation the bread becomes the body of Christ and the wine becomes his blood, so these foods of the pomp of Satan, though of their own nature ordinary food, become profane through the invocation of evil spirits.

"For I would not that ye should have fellowship with demons," says the apostle; since the food of those who are saved and those who perish is separate. We must therefore abstain from these viands not for fear (because there is no power in them); but on account of our conscience, which is holy, and out of detestation of the demons to which they are dedicated, are we to loathe them; and further, on account of the instability of those who regard many things in a way that makes them prone to fall, "whose conscience, being weak, is defiled: for meat commendeth us not to God." "For it is not that which entereth in that defileth a man, but that which goeth out of his mouth." The natural use of food is then indifferent. "For neither if we eat are we the better," it is said, "nor if we eat not are we the worse." But it is inconsistent with reason, for those that have been made worthy to share divine and spiritual food, to partake of the tables of demons. "Have we not power to eat and to drink," says the apostle, "and to lead about wives"? But by keeping pleasures under command we prevent lusts. See, then, that this power of yours never "become a stumbling-block to the weak."