Here the Epistle begins in its main purport. What has gone before is so much exordium. The sharp, stern sentences of vv. 6-10 are like the roll of artillery that ushers in the battle. The mists rise from the field. We see the combatants arrayed on either side. In due order and with cool self-command the Apostle proceeds to marshal and deploy his forces. His truthful narrative corrects the misrepresentations of his opponents, and repels their attack upon himself. His powerful dialectic wrests from their hands and turns against them their weapons of Scriptural proof. He wins the citadel of their position, by establishing the claim of the men of faith to be the sons of Abraham. On the ruins of confuted legalism he builds up an impregnable fortress for Christian liberty, an immortal vindication of the gospel of the grace of God. The cause of Gentile freedom at this crisis was bound up with the person of the Apostle Paul. His Gospel and his Apostleship must stand or fall together. The former was assailed through the latter. He was himself just now "the pillar and stay of the truth." If his character had been successfully attacked and his influence destroyed, nothing, humanly speaking, could have saved Gentile Christendom at this decisive moment from falling under the assaults of Judaism. When he begins his crucial appeal with the words, "Behold, _I Paul_ say unto you" (ch. v. 2), we feel that the issue depends upon the weight which his readers may attach to his personal affirmation. He pits his own truthfulness, his knowledge of Christ, his spiritual discernment and authority, and the respect due to himself from the Galatians, against the pretensions of the new teachers. The comparison is not indeed so open and express as that made in 2 Corinthians; none the less it tacitly runs through this Epistle. Paul is compelled to put himself in the forefront of his argument. In the eyes of his children in the faith, he is bound to vindicate his Apostolic character, defamed by Jewish malice and untruth.