In this dissertation, I argue that the City of God provides a helpful framework for concerned citizens to understand the dynamics that destroy political community. I explore Augustine's claim that Rome's self-understanding (Romanitas) has been shaped into a self-justifying, self-aggrandizing narrative by self-interested citizens. Augustine shows how and why this is the case through his polemic against idolatry, which he describes as the source of injustice.  Thus, I carefully explore Augustine's psychology of idolatry and its three modes: idolatry of the self, which he calls pride, idolatry of earthly goods, which he calls lust, and idolatry of powers, or idolatry per se. Together, he shows, these constitute the dynamic of the earthly city that undermines genuine political community.  Finally, because I read Augustine's City of God as a recasting of Romanitas, re-contextualizing political life so that a new kind of citizenship can arise, I examine this new citizenship, characterizing it as prudent humanitas — a restorative force in politics — one that reconstitutes and heals the political community. I read this prudent humanitas as a development and a fulfillment of themes of Classical, particularly Ciceronian political thought, but one that overcomes the tensions that the classical tradition could, at best, identify: the tension between virtue and happiness, between the public good and the private good, and between love of glory and love of truth. In short, in the City of God, I find a timeless critique of political corruption that serves as the foundation for a prudent yet deeply humane citizenship.