Lactantius, Divine Institutes 5.10

It is worth knowing their piety, that from the things they do mildly and piously it may be understood what sort of things are done by them against the rights of piety. And lest I seem to attack anyone harshly, I will take for myself some poetic person who is the greatest example of piety. In Maro that king than whom none was more just in piety nor greater in war and arms — what proofs of justice did he put forward for us? He had bound behind their backs the hands of those he would send as offerings to the shades, about to sprinkle the flames with slaughtered blood. What can be milder than this piety … than to sacrifice human victims to the dead and to feed the fire with the blood of humans as with oil? But perhaps this was not his own fault, but the poet's, who stained a man outstanding in piety with an outstanding crime. Where then, O poet, is that piety which you praise so often? See: pious Aeneas seizes four youths born at Sulmo, and as many as Ufens raises, living, to sacrifice them as offerings to the shades and to pour captive blood over the flames of the pyre. Why then was he saying at the very time when he was sending bound humans to immolation, 'I would indeed wish to spare the living also,' when he ordered those living whom he held in his power to be killed in place of cattle? But this, as I said, was not that man's fault, who perhaps had not learned letters, but yours: who, though you were learned, still did not know what piety is, and believed that very thing which he did wickedly and detestably to be the duty of piety; namely he is called pious for this one thing, that he loved his father. What of the fact that good Aeneas slaughtered one praying for things not to be scorned? For though adjured by the same father and the hopes of rising Iulus, he by no means spared, inflamed with furies and anger. Would anyone then think this man had any virtue in himself, who both blazed with fury as with stubble and, forgetful of his father's shades by whom he was asked, could not rein in anger? In no way then pious, who killed not only those not resisting but even those praying.

Someone will say here: what then, or where, or of what sort is piety? Surely with those who do not know wars, who keep concord with all, who are friends even to enemies, who love all humans as brothers, who know how to check anger and to soften every fury of the mind with calm moderation. How great then the darkness, how great the cloud of shadows and errors that has covered human breasts, who when they think themselves most pious then become most impious? For the more religiously they serve these earthly images, the more criminal they stand against the name of true divinity. And so for the merit of their impiety they are often denied by heavier evils: whose cause, because they do not know it, is all ascribed to the fault of fortune, and Epicurus's philosophy finds a place, judging that nothing pertains to the gods and that they are touched neither by favor nor moved by anger, because they often see both their despisers blessed and their worshipers wretched. Which happens because when they seem religious and good by nature, they are believed to deserve nothing such as they often suffer. Yet they console themselves by accusing fortune and do not sense that if there were any, it would never harm its worshipers. Deservedly therefore punishment follows this sort of piety, and offended divinity by the crime of humans wrongly religious slaughters them with heavy misfortune: who though they live with holy manners in highest faith and innocence, yet because they worship gods whose impious and profane rites the true God holds in hatred, are alien from justice and from the name of true piety.

Nor is it hard to teach why worshipers of the gods cannot be good and just. For how will they abstain from blood who worship the bloody gods Mars and Bellona? How will they spare parents who worship Jupiter the expeller of his father, or infants born from themselves who worship Saturn? How will they guard chastity who worship a naked and adulterous goddess and as it were prostituted among the gods? How will they abstain from robberies and frauds who have known the thefts of Mercury teaching that to deceive is not fraud but cleverness? How will they check lusts who venerate Jupiter, Hercules, Liber, Apollo and the rest, whose adulteries and shames against males and females are known not only to the learned but are even expressed in theaters and sung, that they may be more known to all? Can humans be just amid these things, who even if they are good by nature are nevertheless trained to injustice by the gods themselves? For to placate the god you worship you need those things by which you know him to rejoice and be delighted. So it happens that the god shapes the life of the worshipers according to the quality of his own divinity, since the most religious worship is to imitate.