The epistle to the Galatians sets before us the great source of the afflictions and conflicts of the apostle in the regions where he had preached the glad tidings; that which was at the same time the principal means employed by the enemy to corrupt the gospel. God, it is true, in His love, has suited the gospel to the wants of man. The enemy brings down that which still bears its name to the level of the haughty will of man and the corruption of the natural heart, turning Christianity into a religion that suits that heart, in place of one that is the expression of the heart of God-an all-holy God-and the revelation of that which He has done in His love to bring us into communion with His holiness. We see, at the same time, the connection between the judaising doctrine-which is the denial of full redemption, and looking for good in flesh and man's will, power in man to work out righteousness in himself for God-in those who hindered the apostle's work, and the attacks that were constantly aimed against his ministry; because that ministry appealed directly to the power of the Holy Ghost and to the immediate authority of a glorified Christ, and set man as ruined, and Judaism which dealt with man, wholly aside. In withstanding the efforts of the judaisers, the apostle necessarily establishes the elementary principles of justification by grace. Traces both of this combat with the spirit of Judaism, by which Satan endeavoured to destroy true Christianity, and of the maintenance by the apostle of this liberty, and of the authority of his ministry, are found in a multitude of passages in Corinthians, in Philippians, in Colossians, in Timothy, and historically in the Acts. In Galatians the two subjects are treated in a direct and formal way. But the gospel is consequently reduced to its most simple elements, grace to its most simple expression. But, with regard to the error, the question is but the more decisively settled; the irreconcilable difference between the two principles, Judaism and the gospel, is the more strongly marked.
God allowed this invasion of His assembly in the earliest days of its existence, in order that we might have the answer of divine inspiration to these very principles, when they should be developed in an established system which would claim submission from the children of God as being the church that He had established and the only ministry that He acknowledged. The immediate source of true ministry, according to the gospel that Paul preached to the Gentiles, the impossibility of uniting the law and that gospel-of binding up together subjection to its ordinances and distinction of days-with the holy and heavenly liberty into which we are brought by a risen Christ, the impossibility, I repeat, of uniting the religion of the flesh with that of the Spirit, are plainly set forth in this epistle.
The apostle begins, at the very outset, with the independence, as to all other men, of the ministry which he exercised, pointing out its true source, from which he received it without the intervention of any intermediate instrument whatsoever: adding, in order to shew that the Galatians were forsaking the common faith of the saints, "all the brethren which are with me." Also, in opening the subject of his epistle, the apostle declares at once, that the doctrine introduced by the judaisers among the Galatians was a different gospel (but which was not really another), not the gospel of Christ.
He begins then by declaring that he is not an apostle either of men or by man. He does not come on the part of men as though sent by them, and it is not by means of any man that he had received his commission, but by Jesus Christ and God the Father who raised Him from the dead. It was by Jesus Christ, on the way to Damascus; and by the Father, it appears to me, when the Holy Ghost said, "Separate to me Barnabas and Paul." But he speaks thus, in order to carry up the origin of his ministry to the primary source of all real good, and of all legitimate authority.  He wishes, as usual, to the assembly, grace and peace from God in His character of Father, and from Jesus in His character of Lord. But he adds here to the name of Jesus, that which belongs to that character of the gospel which the Galatians had lost sight of, namely, that Christ had given Himself for our sins that He might deliver us from this present evil age. The natural man, in his sins, belongs to this age. The Galatians desired to return to it under the pretext of a righteousness according to the law. Christ had given Himself for our sins in order to take us out of it: for the world is judged. Looked at as in the flesh, we are of it. Now the righteousness of the law has to do with men in the flesh. It is man as in the flesh who is to fulfil it, and the flesh has its sphere in this world; the righteousness which man would accomplish in the flesh is directed according to the elements of this world. Legal righteousness, man in the flesh, and the world, go together. Whereas Christ has viewed us as sinners, having no righteousness, and has given Himself for our sins, and to deliver us from this condemned world, in which men seek to establish righteousness by putting themselves on the ground of the flesh which can never accomplish it. This deliverance is also according to the will of our God and Father. He will have a heavenly people, redeemed according to that love which has given us a place on high with Himself, and a life in which the Holy Ghost works, to make us enjoy it and cause us to walk in the liberty and in the holiness which He gives us in this new creation, of which Jesus Himself, risen and glorified, is the head and the glory.
The apostle opens his subject without preamble: he was full of it, and the state of the Galatians who were giving up the gospel in its foundations forced it out from an oppressed, and I may say, an indignant heart. How was it possible that the Galatians had so quickly forsaken him, who had called them according to the power of the grace of Christ, for a different gospel? It was by this call of God that they had part in the glorious liberty, and in the salvation that has its realisation in heaven. It was by the redemption that Christ had accomplished and the grace that belongs to us in Him, that they enjoyed heavenly and christian happiness. And now they were turning to an entirely different testimony; a testimony which was not another gospel, another true glad tidings. It did but trouble their minds by perverting the true gospel. "But," says the apostle, reiterating his words on the subject, "if an angel from heaven, or he [Paul himself], preached anything besides the gospel that he had already preached to them, let him be accursed." Observe here, that he will allow nothing in addition to that which he had preached.
They did not formally deny Christ; they wished to add circumcision. But the gospel which the apostle had preached was the complete and whole gospel. Nothing could be added to it without altering it, without saying that it was not the perfect gospel, without really adding something that was of another nature, that is to say, corrupting it. For the entirely heavenly revelation of God was what Paul had taught them. In his teaching he had completed the circle of the doctrine of God. To add anything to it was to deny its perfection; and to alter its character, to corrupt it. The apostle is not speaking of a doctrine openly opposed to it, but of that which is outside the gospel which he had preached. Thus, he says, there cannot be another gospel; it is a different gospel, but there are no glad tidings except that which he had preached. It is but a corruption of the true, a corruption by which they troubled souls. Thus, in love to souls, he could anathematise those who turned them away from the perfect truth that he had preached. It was the gospel of God Himself. Everything else was of Satan. If Paul himself brought another, let him be anathema. The pure and entire gospel was already proclaimed, and it asserted its claims in the name of God against all that pretended to associate itself with it. Did Paul seek to satisfy the minds of men in his gospel, or to please men? In no wise; he would not thus be the servant of Christ.