12 Or the gods of heaven should be said to be ungrateful if, while they have power to prevent it, they suffer an unhappy race to be involved in so many hardships and disasters. But perhaps they may say something of importance in answer to this, and not such as should be received by deceitful, fickle, and scornful ears. This point, however, because it would require too tedious and prolix discussion, we hurry past unexplained and untouched, content to have stated this alone, that you give to your gods dishonourable reputations if you assert that on no other condition do they bestow blessings and turn away what is injurious, except they have been first bought over with the blood of she-goats and sheep, and with the other things which are put upon their altars.
For it is not fitting, in the first place, that the power of the deities and the surpassing eminence of the celestials should be believed to keep their favours on sale, first to receive a price, and then to bestow them; and then, which is much more unseemly, that they aid no one unless they receive their demands, and that they suffer the most wretched to undergo whatever perils may befall them, while they could ward these off, and come to their aid.
If of two who are sacrificing, one is a scoundrel, and rich, the other of small fortune, but worthy of praise for his integrity and goodness,— if the former should slay a hundred oxen, and as many ewes with their lambkins, the poor man burn a little incense, and a small piece of some odorous substance,— will it not follow that it should be believed that, if only the deities bestow nothing except when rewards are first offered, they will give their favour to the rich man, turn their eyes away from the poor, whose gifts were restricted not by his spirit, but by the scantiness of his means? For where the giver is venal and mercenary, there it must needs be that favour is granted according to the greatness of the gift by which it is purchased, and that a favourable decision is given to him from whom far the greater reward and bribe, though this be shameful, flows to him who gives it. What if two nations, on the other hand, arrayed against each other in war, enriched the altars of the gods with equal sacrifices, and were to demand that their power and help should be given to them, the one against the other: must it not, again, be believed that, if they are persuaded to be of service by rewards, they are at a loss between both sides, are struck motionless, and do not perceive what to do, since they understand that their favour has been pledged by the acceptance of the sacrifices? For either they will give assistance to this side and to that, which is impossible, for in that case they will fight themselves against themselves, strive against their own favour and wishes; or they will do nothing to aid either nation after the price of their aid has been paid and received, which is very wicked. All this infamy, therefore, should be removed far from the gods; nor should it be said at all that they are won over by rewards and payments to confer blessings, and remove what is disagreeable, if only they are true gods, and worthy to be ranked under this name. For either whatever happens, happens inevitably, and there is no place in the gods for ambition and favour; or if fate is excluded and got rid of, it does not belong to the celestial dignity to sell the boon of its services, and the conferring of its bounties.
Source: Against the Heathen (New Advent)