“TWO loves built two cities: the love of self even to contempt of God built the city of Babylon, that is, that of the world and of immorality; the love of God even to contempt of self built the city of God.”
— St. Augustine, The City of God, Bk. XIV, chap. 28
You can read an English translation of The City of God for free here.
The City of God (De Civitate Dei), considered by many as the saint’s most important work, was written over a time span of 13 years (AD 413-426). The pagans’ charges that Christians brought about the fall of Rome [more precisely, the sacking of Rome by the Visigoths in AD 410] prompted Augustine to begin writing this work. In the first part (the first ten books) he refutes the charge and demolishes pagan beliefs. In the second part (books XI-XXII) he shows the two cities – the heavenly city (City of God) and the earthly city (City of Man or City of the Devil) – from their origin, through their growth throughout history, to their final destinations.
Augustine conceives human history as a battle between the City of God, i.e. the followers of Christ and His Church (the sons of light who love God and dedicate themselves to His eternal truths) and the City of Man (the sons of darkness immersed in their self-love, pride and the pleasures of this world). The destiny of the inhabitants of the City of God is eternal happiness, while those who follow the Devil are destined for eternal punishment. Augustine expounds on questions such as the existence of evil, the suffering of the just, original sin, concupiscence, free will, etc. He stresses that the true home of a Christian is heaven; hence it is not an earthly kingdom but heaven to which his affections and efforts should be directed.
