Charles Spurgeon Commentary Galatians 2:15-21

"We being Jews by nature, and not sinners of the Gentiles, yet knowing that a man is not justified by the works of the law but through faith in Jesus Christ, even we believed on Christ Jesus, that we might be justified by faith in Christ, and not by the works of the law: because by the works of the law shall no flesh be justified. But if, while we sought to be justified in Christ, we ourselves also were found sinners, is Christ a minister of sin? God forbid. For if I build up again those things which I destroyed, I prove myself a transgressor. For I through the law died unto the law, that I might live unto God. I have been crucified with Christ; and it is no longer I that live, but Christ living in me: and that [life] which I now live in the flesh I live in faith, [the faith] which is in the Son of God, who loved me, and gave himself up for me. I do not make void the grace of God: for if righteousness is through the law, then Christ died for nought." — Galatians 2:15-21 (ASV)

We who are Jews by nature, and not sinners of the Gentiles, knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified. But if, while we seek to be justified by Christ, we ourselves also are found sinners, is therefore Christ the minister of sin? God forbid. For if I build again the things which I destroyed, I make myself a transgressor. For I through the law am dead to the law, that I might live unto God. I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me. I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain.

Paul is arguing against the idea of salvation by works, or salvation by ceremonies; and he shows, beyond all question, that salvation is by the grace of God through faith in Jesus Christ. Mark the strength of the apostle's argument in the 21st verse: If righteousness come by the law, then Christ is dead in sin. That is to say, there was no need for Christ to die. The crucifixion was a superfluity if men can save themselves by their own good works.

Paul is very emphatic about the matter. He puts it as plainly as possible: If righteousness come by the law, then Christ is dead in vain.