XXV.7 On the luxury of superstition
“They are impious toward the gods,” says Plato, “who deny their existence, or who grant it but maintain that they do not meddle in things here below, or finally who think they are easily appeased by sacrifices : three equally pernicious opinions.”  There Plato says the most sensible things that natural insight has ever said where religion is concerned.
The magnificence of the exterior rite is very much related to the constitution of the state. Good republics have not merely curbed the luxury of vanity, but also of superstition. They have made laws of frugality within religion. Among them are several laws of Solon, several laws of Plato on funerals which Cicero adopted, and finally some of Numa’s laws on sacrifices. 
Birds, says Cicero, and paintings made in a day, are most divine gifts. We offer common things, said a Spartan, so that we will have the means every day of honoring the gods.
The attention men must devote to the worship offered to the deity is quite different from the magnificence of that worship. Let us not offer up our treasures if we do not wish to make the deity see the esteem which we confer on things we should rather disdain.
“What must the gods think of the gifts of the impious,” says Plato admirably, “since a good man would blush to receive presents from a scoundrel ?”
Religion ought not, under pretext of gifts, to require of people what the necessities of the state have left to them ; and as Plato says, chaste and pious men should offer gifts that are like them. 
Nor should religion encourage the expenditures of funerals : what is more natural than to suppress the difference of fortunes in a matter and at moments that equalize all fortunes ?