Verse 21. "I do not frustrate" - ouk aqetw? I do not contemn, despise, or render useless, the grace of God-the doctrine of Christ crucified; which I must do if I preach the necessity of observing the law.
"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!