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.

Paul, however, did not teach that the death of Christ in itself saved men without effort on their part; on the contrary he held that man could attain redemption only through faith in Jesus Christ. Now “faith” meant to him something more than mere belief or trust; it was trust marked by an attitude of sympathy with the divine nature and a readiness to receive that nature into one’s self so that Christ could dwell in man, and the human and the divine natures could be united. In this way to Paul’s mind the Jew was set free from the requirements of the law and obtained justification, that is, gained forgiveness of his sins and reconciliation with God. Faith supplanted law, and made men sons of God. So he wrote: “We being Jews by nature, and not sinners of the Gentiles, yet knowing that a man is not justified by the works of the law, save through faith in Jesus Christ, even we believed on Christ Jesus, that we might be justified by faith in Christ, and not by the works of the law: because by the works of the law shall no flesh be justified.”[311] And again: “But before faith came, we were kept in ward under the law, shut up unto the faith which should afterwards be revealed. So that the law hath been our tutor to bring us unto Christ, that we might be justified by faith. But now that faith is come, we are no longer under a tutor. For ye are all the sons of God, through faith, in Christ Jesus.”[312] This attitude of the apostle was due in part to his own experience, which had shown him the insufficiency of the Jewish law, and also in part to the polemic against Judaism which was a necessary part of his ministry. But his doctrine of justification by faith was not developed for forensic purposes; it was one of his firmest convictions.

When Paul spoke of Christ dwelling in a man, as he frequently did in the Epistle to the Galatians,[313] he meant his words to be taken literally: he held that Christ enters into the man, frees him from the domination of the sinful flesh, and, being a life-giving spirit, brings the Christian from death to life; and that in this way the believer by faith shares in Christ’s death, resurrection, and triumph. Therefore he exhorted the Colossians: “If then ye were raised together with Christ, seek the things that are above, where Christ is, seated on the right hand of God. Set your mind on the things that are above, not on the things that are upon the earth. For ye died, and your life is hid with Christ in God.”[314] Faith to Paul’s mind was a present union with the risen and glorified Christ; it was for him the means of salvation, or rather it was salvation. As he wrote in the sixth chapter of the Epistle to the Romans, he held that through union with Christ man dies to sin and rises to freedom from the bondage of wickedness; he is reborn a new creature and enters into a new spiritual life.[315]

Closely associated with faith is Paul’s doctrine of the Holy Spirit. The word itself (πνεῦμα) was intelligible to both the Greek and Jewish world, but since Paul was not a systematic theologian, it is a matter of much dispute as to what his exact concept of the Holy Spirit was. He evidently thought of the Spirit as a divine objective reality. In some passages he identifies Christ and the spirit of Christ or the spirit of God;[316] from this we may conclude that he probably thought the Holy Spirit to be a mode of the indwelling Christ. But if his concept is not clear to us, we have no difficulty in understanding his ideas as to the operation of the Spirit. He taught that it is the Spirit which assures men of their sonship so that they may address God as their Father; that it transforms the inner man; and that it demands the sanctification of the body, for the body is the temple of the Holy Spirit.[317] From the Spirit come the fundamental virtues—“love, joy, peace, long-suffering, kindness, goodness, faithfulness, meekness, temperance.”[318] Thus the Spirit is the means of continuing the believer in his course and of perfecting him in the Christian life. In common with his contemporaries Paul of course believed that many ecstatic phenomena—speaking with tongues and prophesying, for example—were the gifts of the Spirit; but his instructions to the excitable Corinthians show his good sense and wisdom.[319]

In all his teaching Paul was highly practical. It is not certain that he held a dualistic view of man’s nature in the Greek or Persian sense, but he was well acquainted with the struggle between man’s lower and higher natures and he knew the warring elements within the individual. He frequently contrasted the flesh and the spirit, meaning by the first man’s sinful nature which keeps him in the bondage of wickedness. From this bondage and consequent death he held that man cannot escape by his own powers; but that Christ delivers man from sin and its consequences. This deliverance is an act of grace, a gift from God. We have only to read the Epistles which bear his name to see how wisely he dealt with actual errors and sins, or stirred to concrete acts of righteousness the members of the churches which he had founded.

In most of his writing Paul dwelt on the present salvation which the mystic union with Christ secured, but at times he treated the eschatological nature of salvation, teaching that the full effects of it would be realized when Christ should come to be glorified in his saints. That this day would come quickly the apostle fully believed; then the faithful, dead and living alike, would receive their full reward and the wicked their punishment.

These, briefly, are the fundamental elements in Paul’s doctrine: first, the significance of the death and resurrection of Jesus; second, faith which secures the mystic union with Christ; third, the indwelling Holy Spirit, which completes man’s redemption and moral regeneration. For all Paul doubtless found warrant in the life and words of Jesus, although he seems to have neglected the ethical teachings of the Master. Paul’s views have formed the basis of much of the doctrine of the Church since his time, although his idea of union with Christ through faith soon fell into the background; when it was revived it took on a form very unlike the apostle’s teaching.

We have thus far seen two tendencies in Christian thought. The first appears in the synoptic gospels where Jesus is represented as the mediator and teacher, who interpreted to men the universal loving fatherhood of God and showed them their proper relations to God and to their fellow-men; the other is seen in Paul who taught that through the indwelling Christ salvation was secured. It was inevitable that reflective thought should act upon these teachings, and that in the philosophic environment of the Christian churches, at least outside Judea, attempts should be made to apprehend and to formulate in intellectual terms the nature, life, and mission of Jesus—in other words to create a Christian philosophy or theology. When in the period between 50 and 100 a.d., Christianity came into conflict with Hellenistic philosophy and theosophy this work of building up a Christian philosophy began. This stage is the third represented in the New Testament.

The so-called Epistle to the Hebrews (c. 90 a.d.) is the first document of the New Testament in which the Greek intellectual habit clearly appears. Although the unknown author was writing to Gentile Christians for practical and not doctrinal ends, there is good evidence that he had been influenced by Alexandrian thought. He presents Christianity as the final and absolute religion, emphasizes Christ’s priestly office and his sacrifice, and gives a more philosophical and abstract definition of faith than any other writer of the New Testament. The great example, however, of the effect of the contact of Christianity with Greek thought is furnished by the Gospel of John and the Johannine Epistles.