Verse 21. I do not frustrate the grace of God. The word rendered "frustrate" ayetw means, properly, to displace, abrogate, abolish; then to make void, to render null, Mr 7:9; Lu 7:30; 1 Co 1:19.

The phrase, "the grace of God," here refers to the favour of God manifested in the plan of salvation by the gospel, and is another name for the gospel. The sense is, that Paul would not take any measures, or pursue any course, that would render that vain or inefficacious. Neither by his own life, by a course of conduct which would show that it had no influence over the heart and conduct, nor by the observance of Jewish rites and customs, would he do anything to render that inefficacious. The design is to show that he regarded it as a great principle, that the gospel was efficacious in renewing and saving man, and he would do nothing that would tend to pre, vent that impression on mankind. A life of sin, of open depravity and licentiousness, would do that. And, in like manner, a conformity to the rites of Moses, as a ground of justification, would tend to frustrate the grace of God, or to render the method of salvation solely by the Redeemer nugatory. This is to be regarded, therefore, as at the same time a reproof of Peter for complying with customs which tended to frustrate the plan of the gospel, and a declaration that he intended that his own course of life should be such as to confirm the plan, and show its efficacy in pardoning the sinner, and rendering him alive in the service of God.

For if righteousness come by the law. If justification can be secured by the observance of any law -- ceremonial or moral -- then there was no need of the death of Christ as an atonement. This is plain. If man by conformity to any law could be justified before God, what need was there of an atonement? The work would then have been wholly in his own power, and the merit would have been his. It follows from this, that man cannot be justified by his own morality, or his almsdeeds, or his forms of religion, or his honesty and integrity. If he can, he needs no Saviour -- he can save himself. It follows, also, that when men depend on their own amiableness, and morality, and good works, they would feel no need of a Saviour; and this is the true reason why the mass of men reject the Lord Jesus. They suppose they do not deserve to be sent to hell. They have no deep sense of guilt. They confide in their own integrity, and feel that God ought to save them. Hence they feel no need of a Saviour; for why should a man in health employ a physician? And confiding in their own righteousness, they reject the grace of God, and despise the plan of justification through the Redeemer. To feel the need of a Saviour, it is necessary to feel that we are lost and ruined sinners; that we have no merit on which we can rely; and that we are entirely dependent on the mercy of God for salvation. Thus feeling, we shall receive the salvation of the gospel with thankfulness and joy, and show that in regard to us Christ is not "dead in vain."

{*} "frustrate" "make void" {d} "if righteousness" Heb 7:11