71 But our rites are new; yours are ancient, and of excessive antiquity, we are told. And what help does that give you, or how does it damage our cause and argument? The belief which we hold is new; some day even it, too, will become old: yours is old; but when it arose, it was new and unheard of. The credibility of a religion, however, must not be determined by its age, but by its divinity; and you should consider not when, but what you began to worship.
Four hundred years ago, my opponent says, your religion did not exist. And two thousand years ago, I reply, your gods did not exist. By what reckoning, you ask, or by what calculations, can that be inferred? They are not difficult, not intricate, but can be seen by any one who will take them in hand even, as the saying is. Who begot Jupiter and his brothers? Saturn with Ops, as you relate, sprung from Coelus and Hecate. Who begot Picus, the father of Faunus and grandfather of Latinus?
Saturn, as you again hand down by your books and teachers? Therefore, if this is the case, Picus and Jupiter are in consequence united by the bond of kinship, inasmuch as they are sprung from one stock and race. It is clear, then, that what we say is true. How many steps are there in coming down from Jupiter and Picus to Latinus? Three, as the line of succession shows. Will you suppose Faunus, Latinus, and Picus to have each lived a hundred and twenty years, for beyond this it is that man's life cannot be prolonged?
The estimation is well grounded and clear. There are, then, three hundred and sixty years garter these? It is just as the calculation shows. Whose father-in-law was Latinus? Aeneas'. Whose father was he? He was father of the founder of the town Alba. How many years did kings reign in Alba? Four hundred and twenty almost. Of what age is the city Rome shown to be in the annals? It reckons ten hundred and fifty years, or not much less. So, then, from Jupiter, who is the brother of Picus and father of the other and lesser gods, down to the present time, there are nearly, or to add a little to the time, altogether, two thousand years.
Now since this cannot be contradicted, not only is the religion to which you adhere shown to have sprung up lately; but it is also shown that the gods themselves, to whom you heap up bulls and other victims at the risk of bringing on disease, are young and little children, who should still be fed with their mothers' milk.
Source: Against the Heathen (New Advent)