Galatians 3:19-24

If faith is all that is needed to be declared righteous by God and receive eternal life, then why did God ever give the Law? If God only wanted people to believe, then why bother with bringing up an insanely long list of things to do and not do? Wouldn’t it have been easier and less confusing if instead of giving the law, God instead gave one command – “believe in me”? As Paul argues that the law was never the means by which mankind would be able to justify himself, he arrives at this quandary, “Then why do we have the law?”
It seems at first like a pretty rational question, except that it has built into it a couple of presuppositions that are incorrect.
1) The first incorrect assumption is that the law only exists as a means of earning righteousness with God. The Judaizers and many since them incorrectly view the law this way. They falsely assume that they are supposed to follow it perfectly in order to receive eternal life. The sad truth is that all those who sincerely try to follow the law perfectly, find themselves frustrated and ultimately inadequate. It is because of this failure to completely follow the law that Paul labels these attempted self-justifiers as “cursed.” They have chosen a path by which they will never succeed. It is wholly incorrect for them to assume that the law was ever given so that they could earn justification with God.
2) The second incorrect assumption is that if the law isn’t a means for earning righteousness before God then it should be done away with, as if it can’t serve another purpose. This bifurcation of “if we can’t be justified by the law then we should get rid of it,” is another erroneous way to view the law. It assumes that there isn’t anything else that the law could have been meant to accomplish. Those who heard Paul say, “the law was never given to justify a man before God,” would retort, “then we shouldn’t even have a law!” This false division between “it justifies us” or “if not, then we should throw it away” is not one that is consistent with Scripture.
Paul argues that the law was incredibly necessary. In his own words, the law was meant to be a sort of “schoolmaster” or “guardian” that would bring the simple people of God into the realization that they were sinners in need of justification. By setting the law of God so high that they could not attain to its standard of perfection, people would realize that there would have to be something else besides their own attempts. Paul explained that when Jesus came along and fulfilled the law perfectly then it should have become apparent that He was the one in whom they should place their faith.
As a schoolmaster, the law should have taught everyone that they were never going to be good enough. They should have noticed that they were inadequate and surrendered themselves to the reality that their own attempts at righteousness would always be failures. They should have noticed that Abraham had been justified and declared righteous by God through his faith, 430 years before the law was even given, and they should have followed his example. Now, knowing their inadequacy, all that was left was to turn in faith (like Abraham) from their own self-justifying attempts and rest completely in the perfect righteousness of a sinless Jesus as their only hope of being justified.

Food For Thought: If we are justified by faith, is the law useless? Explain your answer.