Can keeping the law justify anyone before God?
No. Keeping the law cannot justify anyone before God. Paul writes that by the deeds or keeping of the law shall no flesh be justified in His sight. The law gives only awareness of sin and can do nothing but condemn; it had no power to help even the Jew keep it. Justification is by God's righteousness without the law.
Les explains that the law cannot justify anyone because it was never designed to make a person righteous. Paul's argument in verse 20 is that by the deeds or keeping of the law no flesh is justified in God's sight; the law's only function is to give the knowledge or awareness of sin. Les ties this to old Adam, saying the law could do nothing but condemn and had no power even to help the Jew become a law keeper. Then verse 21 introduces the contrast with the little word "but": the righteousness of God is without the law. This is not human righteousness, which is like filthy rags, but God's own righteousness apart from law. Les also keeps in view two precepts: without faith you cannot please God, and without the shedding of blood there is no remission, which points to the cross.
Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin.
Why can't the law justify anyone?
Because the law's demands — "thou shalt, thou shalt not" — apply to every mouth, Jew and Gentile alike, so all the world becomes guilty before God. By the deeds of the law no flesh is justified in His sight; the law's function is to give the knowledge of sin, not justification.
Why can't works-religion people see that the Law cannot justify them?
They cannot see it because they close their eyes to Scripture and insist their church or religion will do it. But the Law only stops every mouth and pronounces all the world guilty; by the deeds of the Law no flesh is justified. Any system requiring works brings condemnation, not justification.
More Questions
Why can't a person be justified by keeping the law?
By the deeds of the law no flesh is justified before God; the law only gives the knowledge of sin and shows that man falls short of the righteousness God demands.