The principal crime of the human race, the highest guilt charged upon the world, the whole procuring cause of judgment, is idolatry. For, although each single fault retains its own proper feature, although it is destined to judgment under its own proper name also, yet it is marked off under the general account of idolatry. Set aside names, examine works, the idolater is likewise a murderer. Do you inquire whom he has slain? If it contributes ought to the aggravation of the indictment, no stranger nor personal enemy, but his own self. By what snares? Those of his error. By what weapon? The offence done to God. By how many blows? As many as are his idolatries. He who affirms that the idolater perishes not, will affirm that the idolater has not committed murder. Further, you may recognize in the same crime adultery and fornication; for he who serves false gods is doubtless an adulterer of truth, because all falsehood is adultery. So, too, he is sunk in fornication. For who that is a fellow-worker with unclean spirits, does not stalk in general pollution and fornication? And thus it is that the Holy Scriptures use the designation of fornication in their upbraiding of idolatry. The essence of fraud, I take it, is, that any should seize what is another’s, or refuse to another his due; and, of course, fraud done toward matt is a name of greatest crime. Well, but idolatry does fraud to God, by refusing to Him, and conferring on others, His honours; so that to fraud it also conjoins contumely. But if fraud, just as much as fornication and adultery, entails death, then, in these cases, equally with the former, idolatry stands unacquitted of the impeachment of murder. After such crimes, so pernicious, so devouring of salvation, all other crimes also, after some manner, and separately disposed in order, find their own essence represented in idolatry. In it also are the cancupiscences of the world. For what solemnity of idolatry is without the circumstance of dress and ornament? In it are lasciviousnesses and drunkennesses; since it is, for the most part, for the sake of food, and stomach, and appetite, that these solemnities are frequented. In it is unrighteousness. For what more unrighteous than it, which knows not the Father of righteousness? In it also is vanity, since its whole system is vain. In it is mendacity, for its whole substance is false. Thus it comes to pass, that in idolatry all crimes are detected, and in all crimes idolatry. Even otherwise, since all faults savour of opposition to God, and there is nothing which savours of opposition to God which is not assigned to demons and unclean spirits, whose property idols are; doubtless, whoever commits a fault is chargeable with idolatry, for he does that which pertains to the proprietors of idols.
Tertullian, On Idolatry