A second reason why the kingdom of God is also called the city of God seems to be this: that a kingdom usually contains a nearly infinite multitude of diverse nations, distinct from one another in languages, customs, and laws, where many have never seen many others of the same kingdom, much less been joined to them in friendship; whereas a city contains only citizens of the same language and the same customs, who are governed by the same laws and usages. The same thing, therefore, is called both kingdom and city, because the inhabitants of the heavenly kingdom, although they are exceedingly many and can scarcely be numbered, and, as St. John says, are gathered out of all nations and tribes and peoples and tongues; and again consist of Angels, Archangels, Principalities, Powers, Virtues, Dominations, Thrones, Cherubim, and Seraphim — who are far more numerous than men, and are distinguished one from another not by nations and peoples and tongues, but by diversity of nature, that is, by specific difference (Rev. 7) — yet they are all true citizens, harmonious, of one mind, and governed by the single and sole law of charity. And so they are all of one heart and one spirit (Rom. 14). And because charity is contrary to hatred, envy, contentions, discords, quarrels, and other sins and vices, therefore far removed from that holy city of Jerusalem are angers, quarrels, contentions, and envies; charity alone reigns there, and with it justice, peace, and joy in the Holy Spirit. A great battle was indeed fought in heaven at the beginning of the creation of the world between Michael the Archangel and the dragon; but the Archangel Michael and his angels, who stood fast in the truth and kept faith and obedience to their Lord, won the victory over the dragon and his angels, who, lifted up in pride, had fallen away from the common Lord Himself (Rev. 12): And that great dragon was cast out, the ancient serpent, who is called the Devil and Satan, who seduces the whole world; and he was cast down to the earth. From that time the holy city, the heavenly Jerusalem, placed peace in its borders; nor has the trumpet of war been heard in it, nor shall it be heard any more for ever (Ps. 147).
What, then, is sweeter, what happier than this city? Those to whom the evils of wars are known — pillaging, slaughter, rapine, conflagrations, sacrileges — can readily proclaim how great is the delight and loveliness of peace. But leaving aside public wars, who is there who, in his own city — indeed, even in his own house — has not experienced how bitter it is to dwell among wrathful or harsh men, who interpret everything in the worse sense? Depart from the unjust man, and evils shall depart from you (Sir. 7), says Sirach. But where shall we go, where we shall not find the unjust? And if the unjust are found everywhere, surely evils will accompany us in every place while we are in this exile. Hear what the same Sirach says of a wicked wife: It is better to dwell with a lion and a dragon than to live with a wicked woman (Sir. 25). And if the companion of one's life is turned by her wickedness into a lion and a dragon, to how many anguishes are most mortals exposed? All who wish to live godly in Christ Jesus shall suffer persecution (2 Tim. 3), says the Apostle. How unhappy, then, is the city of this world, in which one must suffer adversaries and wage wars! For if you wish to be godly, you will suffer persecution from men; but if you choose to be ungodly in order to escape the persecution of men, you will fall into the wrath of the most high and almighty King, who will persecute you and slay you alive and dead, and whose wrath no one can resist. Unhappy and fatal region, in which no one will find true peace! Why, then, do we not love and praise with our whole heart the heavenly city, from which alone all persecution is absent, and in which no wars, no enmities, no quarrels can find a place?