This withdrawal of the Jews from the common fellowship at Antioch was a public matter. It was an injury to the whole Gentile-Christian community. If the reproof was to be salutary, it must be equally public and explicit. The offence was notorious. Every one deplored it, except those who shared it, or profited by it. Cephas "stood condemned." And yet his influence and the reverence felt toward him were so great, that no one dared to put this condemnation into words. His sanction was of itself enough to give to this sudden recrudescence of Jewish bigotry the force of authoritative usage. "The truth of the gospel" was again in jeopardy. Once more Paul's intervention foiled the attempts of the Judaizers and saved Gentile liberties. And this time he stood quite alone. Even the faithful Barnabas deserted him. But what mattered that, if Christ and truth were on his side? _Amicus Cephas, amicus Barnabas; sed magis amicus Veritas._ Solitary amid the circle of opposing or dissembling Jews, Paul "withstood" the chief of the Apostles of Jesus "to the face." He rebuked him "before them all."
II. Peter's conduct is reproved by Paul _in the light of their common knowledge of salvation in Christ_.
Paul is not content with pointing out the inconsistency of his brother Apostle. He must probe the matter to the bottom. He will bring Peter's delinquency to the touchstone of the Gospel, in its fundamental principles. So he passes in ver. 15 from the outward to the inward, from the circumstances of Peter's conduct to the inner world of spiritual consciousness, in which his offence finds its deeper condemnation. "You and I," he goes on to say, "not Gentile sinners, but men of Jewish birth--yet for all that, knowing that there is no justification for man in works of law, only[53] through faith in Christ--we too put our faith in Christ, in order to be justified by faith in Him, not by works of law; for as Scripture taught us, in that way no flesh will be justified."
[53] ἐὰν μὴ has the same partially exceptive force as εἰ μὴ in ch. i. 7, 19. Comp. Rom. xiv. 14; also Luke iv. 26, 27.
Paul makes no doubt that the Jewish Apostle's experience of salvation corresponded with his own. Doubtless, in their previous intercourse, and especially when he first "made acquaintance with Cephas" (ch. i. 18) in Jerusalem, the hearts of the two men had been opened to each other; and they had found that, although brought to the knowledge of the truth in different ways, yet in the essence of the matter--in respect of the personal conviction of sin, in the yielding up of self-righteousness and native pride, in the abandonment of every prop and trust but Jesus Christ--their history had run the same course, and face answered to face. Yes, Paul knew that he had an ally in the heart of his friend. He was not fighting as one that beateth the air, not making a rhetorical flourish, or a parade of some favourite doctrine of his own; he appealed from Peter dissembling to Peter faithful and consistent. Peter's dissimulation was a return to the Judaic ground of legal righteousness. By refusing to eat with uncircumcised men, he affirmed implicitly that, though believers in Christ, they were still to him "common and unclean," that the Mosaic rites imparted a higher sanctity than the righteousness of faith. Now the principles of evangelical and legal righteousness, of salvation by faith and by law-works, are diametrically opposed. It is logically impossible to maintain both. Peter had long ago accepted the former doctrine. He had sought salvation, just like any Gentile sinner, on the common ground of human guilt, and with a faith that renounced every consideration of Jewish privilege and legal performance. By what right can any Hebrew believer in Christ, after this, set himself above his Gentile brother, or presume to be by virtue of his circumcision and ritual law-keeping a holier man? Such we take to be the import of Paul's challenge in vv. 15, 16.