Epistle to Diognetus

But regarding their strictness about meats, their superstition about the Sabbaths, their boasting about circumcision, and their notions about fasting and the new moons, which are utterly ridiculous and unworthy of attention—I do not think you need to learn anything from me. For, to accept some of the things created by God for human use as properly made, and to reject others as useless and redundant—how can this be lawful? And to falsely speak of God, as if He forbade us to do good on the Sabbath days—how is this not impious? And to take pride in the circumcision of the flesh as proof of being chosen, and as if, because of it, they were specially loved by God—how is this not a cause for ridicule? And regarding their observing months and days, as if relying on the stars and the moon, and organizing, according to their own preferences, the appointments of God and the changes of the seasons, some for celebrations and others for mourning—who would consider this part of divine worship rather than a demonstration of folly? I suppose, then, you are sufficiently convinced that the Christians properly abstain from the vanity and error common to both Jews and Gentiles, and from the meddlesome spirit and vain boasting of the Jews; but you must not hope to learn the mystery of their unique mode of worshipping God from any mortal.