2 I speak thus to you, Laeta my most devout daughter in Christ, to teach you not to despair of your father's salvation. My hope is that the same faith which has gained you your daughter may win your father too, and that so you may be able to rejoice over blessings bestowed upon your entire family. You know the Lord's promise: “The things which are impossible with men are possible with God.” It is never too late to mend. The robber passed even from the cross to paradise. Nebuchadnezzar also, the king of Babylon, recovered his reason, even after he had been made like the beasts in body and in heart and had been compelled to live with the brutes in the wilderness. And to pass over such old stories which to unbelievers may well seem incredible, did not your own kinsman Gracchus whose name betokens his patrician origin, when a few years back he held the prefecture of the City, overthrow, break in pieces, and shake to pieces the grotto of Mithras and all the dreadful images therein? Those I mean by which the worshippers were initiated as Raven, Bridegroom, Soldier, Lion, Perseus, Sun, Crab, and Father? Did he not, I repeat, destroy these and then, sending them before him as hostages, obtain for himself Christian baptism?
Even in Rome itself paganism is left in solitude. They who once were the gods of the nations remain under their lonely roofs with horned-owls and birds of night. The standards of the military are emblazoned with the sign of the Cross. The emperor's robes of purple and his diadem sparkling with jewels are ornamented with representations of the shameful yet saving gibbet. Already the Egyptian Serapis has been made a Christian; while at Gaza Marnas mourns in confinement and every moment expects to see his temple overturned. From India, from Persia, from Ethiopia we daily welcome monks in crowds. The Armenian bowman has laid aside his quiver, the Huns learn the psalter, the chilly Scythians are warmed with the glow of the faith. The Getæ, ruddy and yellow-haired, carry tent-churches about with their armies: and perhaps their success in fighting against us may be due to the fact that they believe in the same religion.
Source: Letters (New Advent)