What does Galatians 2:21 mean?

Paul has been arguing, strongly, that it is totally illegitimate to add requirements such as good deeds or rituals to the gospel of salvation. We are saved by grace alone, through faith alone, and any inclusion of works conflicts with that good news (Galatians 1:8–9; 2:16). In the prior verse, Paul dramatically explained why this does not offer us a license to sin: those who are saved by grace through faith have "died" to sin, and will seek to obey God, even if they sometimes slip.

Here, Paul delivers his final argument in this line of thinking about being justified or declared righteous by God. He has already shown that we can only be condemned by the law. If somehow he were wrong, though, and it was possible to be made righteous before God by the works of the law, why did Jesus die? What would be the point? We could all stay on the path of the law and be saved. But the law cannot save, so Paul will not nullify—he will not ignore, or make worthless—God's grace. Paul will instead die to the law. He will place all of his faith in Christ's righteousness and Christ's death on the cross. That sacrifice in his place, not Paul's own works, will be his only means of being counted as righteous before God.