Law Vs. Gospel

As we have been working through this letter that Paul wrote, If you haven’t noticed already the big question Galatians attempts to answer is: How do we relate to God? How do we engage with Him? Do we experience God as a reward for good works? Do we gain more of an understanding of God by keeping His laws of nature, conscience or Scripture? Or do we encounter God by His grace? Do we enjoy Him through faith in His promises? How do we relate to God? Paul was arguing for that we are justified by faith and not through the law. What is the purpose of the law then? What is the difference between law and grace?