St. Augustine of Hippo was a well-known philosopher and theologian. He was a bishop in the city of Hippo Regius, thus the name St. Augustine of Hippo. Augustine is considered as one of the most significant character in the advancement of Western Christianity. For this, he was also considered as one of the father of the church. Augustine strongly believes in the notions of original sin and just war. St. Augustine is also considered the Doctor of the Church as well as the supporter of the Augustinian Religious Order. He is known as a great teacher on subjects such as salvation and grace. Two of his greatest works are The Confessions and the City of God.St. Augustine of Hippo was born in Tagaste in 354. He is known to have lived a life which cured the gap or disparity between the ancient Pagan Rome and the medieval period of the Christians. His work, the Confession was the main indicator of the transition from the ancient Pagan Rome to the Christian middle ages (Augustine The Confessions). Augustine began his life as a Manichee and he espoused belief on Neo-Platonism before he began his life as the bishop of Hippo. Roman African Christianity was considered as one of the most pure form of Christianity. This is mainly because they were not much influenced by the corrupt Roman or Italian customs. The highest rupture on St. Augustine’s era was when the Donatists tore away from the Catholic Church. The reason behind the rift is the matter of Christian association with the Roman pagan authorities. All through his life, Augustine remain firm on his stand for the religion of church. His religious study gives more emphasis on the original sin and the great need for baptism at birth.The City of God took Augustine almost thirteen years to write. In the City of God he laid out new groundwork in the subject of Christian apologetics as well as on the examination of Christian history. The said book could be divided into two parts. The first part of The City of God is made up of the author’s denial of the allegation made by the Roman citizens who believes that Christianity is to blame for the fall of Rome. The second part on the other hand centered most on the Augustine’s two cities, the City of God and the City of Man. The City of God, which embodies Jerusalem, has a celestial foundation as well as a perpetual future. The City of Man, which embodies Babylon, was depicted to have human origin and a worldly or mundane fate in contrast to the City of God (Augustine City of God).Augustine wrote The City of God to clarify the relationship of Christianity with rival religions, philosophies, as well as on the Roman administration to which it had been interwoven. The said treatise was written after Rome was tore apart by the Visigoths. As was already stated earlier the book was partly written to defend Christianity from the Roman citizens who believe that the fall of Rome was because they abandoned their pagan religion. Augustine set out to prove that the city of God would eventually triumph over the City of Man. Regardless of Christianity’s title as the official religion of the realm, Augustine announced its significant to be more spiritual than political. Augustine stated that Christianity should concern itself more on the celestial City of Jerusalem instead of earthly politics which is common in Rome. His religious teachings held up and aided to characterize the division of church and State which distinguishes part of the Western politics all throughout the Medieval era. The book bestowed human history as a clash between the two cities. The City of God is features people who gave up material pleasures and devoted themselves to the endorsement of Christian principles. The City of Man is made up of people who have drifted apart from the City of God. Christianity is denoted to be at the center of the city of God. The book was also mostly composed of numerous excursions on philosophical matters and staging of defects in pagan religions (Augustine City of God).Plato had greatly influenced Augustine’s philosophy. This is very evident on the fact that both believe in the idea of two worlds. Wherein Plato’s worlds are composed of the world of forms and the unintelligible world, Augustine worlds’ are the City of God and the City of Man. Whereas Plato used the term “the good”, Augustine used “god” and whereas Plato used the term “the forms” Augustine used “the divine”. Plato believes that the forms could only be obtained by philosophers or those people who have rational souls. Plato believes that the understanding of forms should undergo a rational procedure which led him to the conclusion that the only people fit to rule are the philosopher kings (Augustine City of God).Undoubtedly, Augustine adopted this view of Plato. However, he went on to expand it to the area of Christianity. The numerous forms which Plato deems to be the realms of the intelligible and the rational are the very characterization of Augustine’s concept of God. Thus, Augustine could be seen to have accepted Plato’s theories and then redefine those theories of forms and knowledge to his notion of God.The time when Augustine was ordained the bishop of Hippo also proved to be a time of political and theological turbulence because while the barbarians create chaos all over the empire divisions and sacrileges caused serious pressure on the Church’s part. Augustine took part on the theological battle endlessly defending the church against the attacks made on it by the nonbelievers. Two of the major conflicts fought by St. Augustine were with the Donatists and the Pelagians. All throughout the conflict St. Augustine was able to work out his doctrines on original sin and divine grace. Augustine’s concept of freedom was largely tied up with his concept of the original sin and divine grace. Augustine argued that freedom resulted from grace releasing humans from the penalties made by sin. Sin, according to him, produced the rift between God and mankind. It is also the price for and materialization of the said rift. Grace plays an important part in bridging the said rift since grace makes the good obvious in the same manner that grace makes the good capable to be done. The Roman Catholic Church found great approval in the religious facets of the said doctrines of Augustine. The said doctrines helped in the conflict with the Donatists and Pelagians. Against the doctrine of Pelagian, Augustine argued that sin is the outcome of human defiance and that human nature could do nothing to change that particular outcome. Mankind, according to Augustine, was saved from this sin because of God’s divine grace. Against the Manichaeism on the other hand, Augustine forcefully defended the freewill, or liberty with the help of his concepts on original sin and divine grace (Augustine City of God; Augustine The Confessions).Augustine believes that the body is some kind of a container or an instrument for the soul. Augustine argued that neither body nor soul would suffer complete annihilation. Here is where Augustine’s notion of body departed from that of the Romans and the Greeks. This could also be seen based on Aristotle’s notion of body and soul. Aristotle did not imply that soul is immortal. Aristotle’s belief on the interrelatedness of body and soul does not have much in accordance with Augustine’s own notion that body and soul could possibly survive even after death called upon a person’s door when the classical notion holds that the soul would be separated from that of the body when death comes into a person’s life. Romans and Greeks do not hold Augustine’s belief that the body could rejoin soul after death in what is called resurrection.One could see that Augustine’s work was largely influenced by his own experiences in life. He lived in a time where the Roman Empire was in deep deterioration and Christianity was making its progress into becoming the official religion. Augustine’s era was filled with great political and religious turbulence. In fact, even his own spiritual struggles mirror the historical transition from the Roman’s fading ancient pagan beliefs to the medieval era of the Christian religion. The Confession, one of his most famous works, discloses many things which happened during his formative years wherein he tried hard to fight his sensual or earthly desires, find faith, and comprehend religious as well as philosophical principles. The City of God on the other hand, showed how Augustine valiantly tried to defend the Christian religion from the non-believers. Thus, as many prolific writers were, Augustine also proved to make use of his own personal experiences from life in terms of developing his own doctrines (Augustine City of God; Augustine The Confessions).