If St. Paul's epistles are taken in those groups into which they naturally divide themselves, we find that in the first group, that of the two epistles to the Thessalonians, all his favourite topics are present as it were in the germ, but nothing that is specially characteristic of him is yet developed. The free admission of the Gentiles into the Church is, with the accompanying hostility of the Jews, assumed[4], but not much insisted upon; but in the interval between these epistles and that to the Galatians the subject had gained fresh and poignant interest. A party of Christians having their centre at Jerusalem had been trying – in spite of the decision of the apostolic council at Jerusalem – to reimpose upon the consciences of Gentile Christians, and with especial success in the Galatian province, the obligation of circumcision; or in other words had been trying to make it evident that the Church of God was as much as ever the people of the Jews, and that Gentiles could only become Christians by becoming also Jewish proselytes pledged to keep the law of Moses. In view of this attempt St. Paul re-embarks upon his great campaign for the catholicity of the Church, and in his epistles of the second group[5] (especially those to the Galatians and the Romans) the catholicity of Christianity is vindicated controversially upon the basis of the principle of justification by faith, not by works of the law.
The meaning and real importance of this doctrine ought not to be hard for us to understand. To be justified means to be accepted or acquitted by God. The Judaizers – that is the Christian representatives of the narrower religious spirit of Israel – held that, as God's covenant was with the Jews only, so men could obtain acceptance simply by the observance of that Mosaic law which was to the Jew at once the expression of the divine selection of his race, and the grounds of his arrogant contempt for all who had not 'Abraham to their father[6].' But St. Paul had made trial of that theory, and had found it wanting. The observance of the law and the glorying in Jewish privileges had brought him no peace with God: had in fact served only to produce and deepen a sense of inner alienation from God and conviction of sin. Thus in acknowledging the messiahship of that Jesus whom the chosen people had rejected and surrendered to be crucified, he was abandoning utterly and for ever the standing-ground of Jewish pride: he was acknowledging that the only divine function of the law was to convince men of sin, and of their need of pardon and salvation: he was taking his stand as a sinner among the Gentiles, and humbly welcoming the unmerited boon of pardon and acceptance from the hand of the divine mercy in Christ Jesus. When St. Paul in familiar arguments, from the witness of the Old Testament itself, and from the moral experience of men, convicts the law of inadequacy as an instrument of justification, his reasoning is full of a strong feeling and conviction bred of his own experiences. The true means of justification, he has come to perceive, is faith, that is, the simple acceptance of the divine favour freely offered, and this is something that belongs to no special race, but to all men as such. For all men everywhere, to whom the light comes, can know that they are sinners in the sight of God, and can accept simply from the hand of the divine bounty the unmerited boon of forgiveness and acceptance in Christ. Thus, if faith and faith alone is that whereby men are justified or commended to God, then at once the catholic basis of the reconstituted Church is secured. All men can belong to it who can feel their need and hear the Gospel and take God at His word. This is the great principle vindicated in the compressed and fiery arguments of the Epistle to the Galatians, and then subsequently developed in the calmer and orderly procedure of the Epistle to the Romans.
But in the next group of epistles, written out of that captivity at Rome the record of which closes the Acts of the Apostles, the same doctrine of the catholicity of the Church is developed from a different point of view. Now it is the thought of the person of Christ which has come to occupy the foreground. All along St. Paul had believed that Christ was the Son of God, the divine mediator of creation, who in these latter days had for our sakes humbled Himself to be made man[7]. But this thought of Christ's person is elaborated and brought into prominence in the third group of epistles[8], especially in the Epistle to the Colossians. A tendency derived from Jewish sources was manifesting itself among some of the Asiatic Christians to exalt angelic beings, conceived probably as representing divine attributes and powers, into objects of religious worship[9]. There is a certain spurious humility which has in many ages, and not least in the Christian Church, led men to shrink from direct approach to the high and holy God and to resort to lower mediators, as more suitable to their defiled condition and weakness. This sort of spurious humility was already detected by St. Paul, in company with other Judaizing and falsely ascetic tendencies, as a peril of the Asiatic churches, and especially of the Colossians.
But he will make no terms with it. Christ he teaches is the only and the universal mediator, the one and only reconciler of all things to the Father. And He is this because of the position that belongs to His person in the universe as a whole. He, as the Father's image or counterpart, is His unique agent in all the work of creation. All created things whatever, from the lowest to the highest, seen or unseen, be they thrones or dominions or principalities or powers, are the work of His hand. All were created through Him and have Him for their end or goal, and He is the sustaining life of the whole universe in all its parts. 'In Him all things consist' or have their unity in a system. And because He occupies this position in the whole universe, therefore a similar position and sovereignty belong to Him in the spiritual kingdom of redemption. There too He is, through His manhood and His sacrificial death upon the cross, the unique author of the reconciliation with God. He is by His spirit the inherent life of the redeemed, and the goal of all their perfecting. There is, in fact, no divine quality, or attribute, or activity of God towards His creatures which is not His. In Him it pleased the Father that all the fulness of divine attributes and offices should dwell, and in Him as Son of God made man dwells all this fulness bodily. The divine attributes, that is, are not committed to a number of different mediators. They exist and are exercised in Him and in Him alone. It follows therefore as a matter of course from this position of Christ in the universe and in the church that the redemption effected by Him must be universal in range and must extend equally and impartially to all. There 'cannot be Greek and Jew, circumcision and uncircumcision, barbarian and Scythian, bond and free, but Christ is all and in all.'
Thus in the Epistle to the Colossians[10] the doctrine of the catholicity of Christianity is again vindicated controversially, and logically based upon the catholic character of Christ and upon His universal function in creation and redemption; and in the contemporary Epistle to the Ephesians, without note of controversy, the doctrine of the catholic church, the brotherhood of all men in Christ, the doctrine which is, we may truly say, the culmination of all St. Paul's teaching, is allowed to develope itself in all its glory on the assumed basis of that teaching about Christ's person which had made any narrower idea of the church already seem incongruous and impossible. In the earlier dispensation in which the covenant of God was with one people, St. Paul can see only a preparatory process through which the eternal purpose of God could at last be realized, and out of which His eternal secret could at last be disclosed. That purpose so long kept secret, and now revealed, is to gather together all nations and classes of men into the one Church of God, one organized body, one brotherhood in which all men are to find their salvation, and through which is to be realized an even wider purpose for the whole universe. In this doctrine of the catholic church St. Paul finds the expression of all the length and breadth and height and depth of the divine love. Its length, for it represents an age-long purpose slowly worked out; its breadth,