The philosophies of Saint Augustine were remarkable and perhaps revolutionary for his lifetime. Augustine believed in a unity of government and church, a unity in which God is the sole ruler. Augustus fundamental beliefs were based on the idea that man was created in likeness of God, in order to carry out God's work on earth. (Dietrich, St. Augustine) The philosophies of Augustus can best be seen in his work, The City of God, in which he describes the principals he feels life is based on.
With the collapse of Rome to the Visigoths, the Christians views were held responsible for the damage. Augustine defended these views with The City of God (Early Christianity, 185.) This city, he wrote, is " surpassingly glorious, whether we view it as it still lives by faith in this fleeting course of time, and sojourns as a stranger in the midst of the ungodly, or as it shall dwell in the fixed stability of its eternal seat . . ." There is another city of which he also writes: the earthly one. Of it, he says, "though it be mistress of nations, it itself is ruled by its lust of rule." Throughout the City of God, he traces the journeys of these two cities, from the time they were founded, to how they relate with one another, the conduct of their life, and finally, their ultimate end (Hurd, City of God analysis.) .
God created Adam and Eve in perfect nature, but the selfishness of the individual caused them to sin. Hence they began to live not for God's will but for themselves. " No member of this race would ever have died if not for the first two merited this death by disobedience." (Early Christianity, 185) It was the original sin that caused the earthly city to be the destination of mankind. Without the will of God mortals will never achieve true happiness. "The happiness of man can come not from himself but only from God, and that to live according to oneself is to sin, and to sin is to lose God- (Early Christianity, 186) Augustine knew that God forgave, and hence resolved a way for man to see his grace; while still allowing mortals to live in a condemned world because of their own inflictions.