While the first ten books of The City of God are directed towards addressing the charges of the pagan critics who maintained that Christianity was responsible for the sack of Rome in 410 A.D., in the remaining books (XI-XXII) Augustine directs his attention to the arc of Scripture and the task of narrating the intertwined history of the “two cities.”  The following is one of the central quotes in which Augustine makes clear his understanding of the differentiation between the two cities:

“Two cities, then, have been created by two loves:  that is, the earthly by love of self extending even to contempt of God, and the heavenly by love of God extending to contempt of self.  The one, therefore, glories in itself, the other in the Lord; the one seeks glory from men, the other finds its highest glory in God, the Witness of our conscience.  The one lifts up its head in its own glory; the other says to its God, ‘Thou art my glory, and the lifter of mine head.’ [Ps. 3:3]  In the Earthly City, princes are as much mastered by the lust for mastery as the nations which they subdue are by them; in the Heavenly, all serve one another in charity, rulers by their counsel and subjects by their obedience.  The one city loves its own strength has displayed in its mighty men; the other says to its God, ‘I will love Thee, O Lord, my strength’” (XIV.28). ¹