Outside of Jesus, there is no person more central to Christianity than Paul. Apostle, missionary, and former persecutor of the faith, Paul brought the Gospel of Jesus Christ to Gentiles all across the Roman Empire. Half of the New Testament is either ascribed to him or about him. By the end of his life, the people who believed in Jesus were organized into churches, communities of faith that had confessions and liturgies and bishops and deacons. Central to his thinking was that sinners are justified by grace through faith.