Galatians 2:21

In thus attaching himself devotedly to Christ, the Christian escapes the charge of refusing and thwarting the free gift of justification which God has offered to him in His Son. He has made his choice of Christ, and not of the Law. On the other hand, if he had chosen the Law, and gone to it, and not to Christ, in his search for righteousness, he would have practically declared the death of Christ to be a useless and unnecessary sacrifice.

Frustrate. — An exactly literal translation of the Greek word, which means “to render nugatory or ineffectual.” The grace of God goes forth with a certain mission to perform; but the Judaising party, by still clinging to the Law, prevented it from taking effect, and made it “return void” unto its Giver.

If righteousness come by the law. — What all men seek is justification in the sight of God. This is given to the just or righteous. But there were two ways of becoming thus just or righteous. The Law professed to make righteous those who complied with its provisions. But this was only a profession, for no one could really keep the Law. The Christian, therefore, rightly falls back upon faith in Christ, which brings him both an imputed righteousness, and also, in part, at least, a real righteousness. A deep and genuine faith in Christ is allowed to atone for the many unavoidable breaches of the Law, and that faith by degrees operates a real and vital change in the character and life of the man.

Then Christ is dead in vain. — If the Law had been enough to give actual righteousness to its votaries, and with righteousness the judicial declaration of freedom from guilt, then there would have been nothing for Christ to die for. His death would have had no object and been of no benefit to mankind.