Paul was the chief leader in extending the gospel to the Gentiles, and so much did he overshadow the other missionaries that his work and teaching mark the second period in the history of Christianity. Although no account can here be given of his life and experiences, it is necessary to have these in mind to understand his influence. Especially important is it to remember that he was a trained Jew, familiar with the Old Testament and with the theological doctrines of his people; nor was he unacquainted with the ideas and the language of the Greek world, or untouched by the mysticism of his day. A Roman citizen by birth, a Hebrew of the Hebrews by descent and education, he was well fitted to play his great rôle as the apostle who was to carry Christianity out of Judaism to the Gentiles. He was, however, no systematic theologian to lay down a logical body of doctrine as a Greek might have done, and his writings were all occasional. Furthermore he had not been a companion of Jesus, but was one who believed that by an extraordinary experience he had come directly into knowledge of the risen Christ. Yet if Paul was not a systematic theologian, he combined with his intense religious devotion a keen habit of mind which made the fundamental elements of his thought stand out clearly. To him Christ’s death and resurrection were the great facts of salvation, the means whereby man was redeemed from sin. If we read the Epistle to the Galatians, perhaps the earliest of the Pauline epistles (c. 46-50 A.D.), which contains much autobiographical material, we find certain ideas set forth there which are repeated again and again in his other writings. We can hardly do better than to begin with this letter. First, Christ is stated to be the redeemer of men from their sins; this is shown by the words of the greeting: “Grace to you and peace from God the Father, and our Lord Jesus Christ, who gave himself for our sins, that he might deliver us out of this present evil world, according to the will of our God and Father.” The suffering of the good for the sins of others, as we have already seen, was an idea familiar to the Jews, and it was easy for a Jewish convert to relate the death of Jesus to the prophecy in the fifty-third chapter of Isaiah. Paul saw in the death and the resurrection of Jesus the proof that he was the Christ. The vicarious character of Christ’s death was probably an element in all apostolic teaching. On it and the mystic indwelling of Christ, Paul wholly based his preaching.