For if righteousness] If justification and salvation come by an observance of the law, then Christ is dead in vain; his death is useless if an observance of the law can save us; but no observance of the law can save us, and therefore there was an absolute necessity for the death of Christ.

1. THE account of the prevarication of Pet. in the preceding chapter teaches us a most useful lesson. Let him who assuredly standeth take heed lest he fall. No person in a state of probation is infallible; a man may fall into sin every moment; and he will, if he do not walk with God. Worldly prudence and fleshly wisdom would have concealed this account of the prevarication of Peter; but God tells truth. This the fountain of it; and from him we are to expect not only nothing but the truth, but also the whole truth. If the Gospel were not of God we had never heard of the denial and prevarication of Peter, nor of the contention between Paul and Barnabas. And these accounts are recorded, not that men may justify or excuse their own delinquencies by them, but that they may avoid them; for he must be inexcusable who, with these histories before his eyes, ever denies his Master, or acts the part of a hypocrite. Had the apostles acted in concert to impose a forgery on the world as a Divine revelation, the imposture would have now come out. The falling out of the parties would have led to a discovery of the cheat. This relation, therefore, is an additional evidence of the truth of the Gospel.

2. On, I through the law am dead to the law, &c., pious Quesnel makes the following useful reflections: "The ceremonial law, which is no more than a type and shadow of him, destroys itself by showing us Jesus Christ, who is the truth and the substance. The moral law, by leaving us under our own inability under sin and the curse, makes us perceive the necessity of the law of the heart, and of a saviour to give it. The law is for the old man, as to its terrible and servile part; and it was crucified and died with Christ upon the cross as well as the old man. The new man, and the new law, require a new sacrifice. What need has he of other sacrifices who has Jesus Christ? They in whom this sacrifice lives, do themselves live to God alone; but none can live to him except by faith; and this life of faith consists in dying with Christ to the things of the present world, and in expecting, as co-heirs with him, the blessings of the eternal world. And who can work all this in us but only he who lives in us? That man has arrived to a high degree of mortification, who can say Christ liveth in me, and I am crucified to the world. Such a one must have renounced not only earthly things, but his own self also." 3. Is there, or can there be, any well grounded hope of eternal life but what comes through the Gospel? In vain has the ingenuity of man tortured itself for more than 5000 years, to find out some method of mending the human heart: none has been discovered that even promised any thing likely to be effectual. The Gospel of Christ not only mends but completely cures and new makes infected nature. Who is duly apprised of the infinite excellency and importance of the Gospel? What was the world before its appearance? What would it be were this light extinguished? Blessed Lord! let neither infidelity nor false doctrine rise up to obscure this heavenly splendour!

John Gill's Bible Commentary

Greek Textus Receptus

The grace of God (thn carin tou qeou). Cariv is, primarily, that which gives joy (cara). Its higher, Christian meaning is based on the emphasis of freeness in a gift or favor. It is the free, spontaneous, absolute loving kindness of God toward men. Hence often in contrast with the ideas of debt, law, works, sin. Sometimes for the gift of grace, the benefaction, as 1 Cor. xvi. 3; 2 Cor. viii. 6, 19; 1 Pet. i. 10, 13. So here: the gracious gift of God in the offering of Christ.

Is dead (apeqanen). More correctly, died; pointing to the historical incident.

In vain (dwrean). Groundlessly, without cause. See on 2 Thessalonians iii. 8. The sense here is not common. It is not found in Class., and in N.T. only John xv. 25. In LXX, see Psalm xxxiv. 7, 19; cviii. 3; cxviii. 161; 1 Samuel xix. 5; Sir. xx. 23; xxix. 6. Comp. Ignatius, Trall. 5. Paul says: "I do not invalidate the grace of God in the offering of Christ, as one does who seeks to reestablish the law as a means of justification; for if righteousness comes through the law, there was no occasion for Christ to die."

ADDITIONAL NOTE ON VERSES 14-21.

The course of thought in Paul's address to Peter is difficult to follow. It will help to simplify it if the reader will keep it before him that the whole passage is to be interpreted in the light of Peter's false attitude - as a remonstrance against a particular state of things.

The line of remonstrance is as follows. If you, Peter, being a Jew, do not live as a Jew, but as a Gentile, as you did when you ate with Gentiles, why do you, by your example in withdrawing from Gentile tables, constrain Gentile Christians to live as Jews, observing the separative ordinances of the Jewish law? This course is plainly inconsistent.

Even you and I, born Jews, and not Gentiles - sinners - denied the obligation of these ordinances by the act of believing on Jesus Christ. In professing this faith we committed ourselves to the principle that no one can be justified by the works of the law.

But it may be said that we were in no better case by thus abandoning the law and legal righteousness, since, in the very effort to be justified through Christ, we were shown to be sinners, and therefore in the same category with the Gentiles. Does it not then follow that Christ is proved to be a minister of sin in requiring us to abandon the law as a means of justification?

No. God forbid. It is true that, in seeking to be justified in Christ, we stood revealed as sinners, for it was Christ who showed us that we could not be justified by the works of the law; that all our legal strictness only left us sinners. But the inference is false that Christ is thereby shown to be a minister of sin.

For to say that Christ is a minister of sin, is to say that I, at his bidding, became a transgressor by abandoning the law, that the law is the only true standard and medium of righteousness. If I reassert the obligation of the law after denying that obligation, I thereby assert that I transgressed in abandoning it, and that Christ, who prompted and demanded this transgression, is a minister of sin.

But this I deny. The law is not the true standard and medium of righteousness. I did not transgress in abandoning it. Christ is not a minister of sin. For it was the law itself which compelled me to abandon the law. The law crucified Christ and thereby declared him accursed. In virtue of my moral fellowship with Christ, I was (ethically) crucified with him. The act of the law forced me to break with the law. Through the law I died to the law. Thus I came under a new principle of life. I no longer live, but Christ lives in me. If I should declare that righteousness is through the law, by reasserting the obligation of the law as you, Peter, have done, I should annul the grace of God as exhibited in the death of Christ: for in that case, Christ's death would be superfluous and useless. But I do not annul the grace of God.

Robertson's NT Word Studies