Tertullian · a new plain-English translation from the original language
Augustus, the very architect of the empire, did not even want to be called "lord"—for that too is a title belonging to God. I will readily call the emperor "lord," but in the ordinary sense, not when I am compelled to use it in place of the word "God." In every other respect I am a free man in relation to him; for I have only one Lord, God almighty and eternal—the same who is his Lord too. He who is father of his country—how can he be its lord? A title of affection is more welcome than one of power; even in families, fathers are called rather than lords.
So far is it from being right that the emperor should be called God, a thing that simply cannot be believed—not merely a most disgraceful flattery, but a ruinous one. It's as though, having one emperor, you were to hail another: wouldn't you provoke the deepest and most implacable resentment in the one you already had—a resentment that even the man you flattered ought to fear on his own behalf? Be religious toward God, if you want him to be favorable to the emperor! Stop believing there is another god, and so stop calling this man "god" too, when it is precisely God he needs! If flattery of this sort, calling a man God, feels no shame at the lie, let it at least fear the ill omen: it has always been a curse to call a Caesar "god" before his apotheosis.