Saint Augustine was a Latin philosopher and theologian from the Africa Province of the Roman Empire and is generally considered as one of the greatest Christian thinkers of all times. His writings were very influential in the development of Western Christianity. According to his contemporary Jerome, Augustine "established anew the ancient Faith." In his early years he was heavily influenced by Manichaeism and afterward by the Neo-Platonism of Plotinus. After his conversion to Christianity and his baptism in 387, Augustine developed his own approach to philosophy and theology, accommodating a variety of methods and different perspectives. He believed that the grace of Christ was indispensable to human freedom, and he framed the concepts of original sin. Augustine developed the concept of the Catholic Church as a spiritual City of God, distinct from the material Earthly City. Augustine's City of God was closely identified with the Church, the community that worshiped the Trinity.