In Galatians 3:23-25, Paul talks more about this question: if God's plan was that we would be justified by faith in Jesus Christ, what was the point of God giving us the law through Moses?
Paul's answer: the law was put in place to govern and watch over God's people until Jesus Christ came. Paul compares God's law to a guardian who takes care of you when you are still young, and how when you become an adult that guardian no longer has authority over you. Like a guardian taking care of children, God's law was there to watch over God's people and to protect them from harm. But when those children became mature, they were no longer subject to a guardian. The babysitter is gone. In the same way, when Christ arrived, we no longer needed to be under the supervision of the law, because our real, permanent king has come.
In verses 26 and 27, Paul says that "all of you who were baptized into Christ have clothed yourselves with Christ." We are justified by faith in Christ, and when we get baptized to evidence our faith, we are clothed with Christ and there is now no doubt as to whom we believe and to whom we belong. Don't just put your faith in Jesus. Make sure to evidence that faith by getting baptized too.
Finally, in verses 28 to 29, Paul says that because we are all justified by faith in Christ, distinctions that used to seem so important -- Jew or Gentile, slave or free, male or female -- are no longer as important. What matters most is that through faith in Christ we all are children of Abraham and heirs of the righteousness that God promised to Abraham's seed (v29). It's a good reminder that when we look at other Christians, we are to see past distinctions such as race, gender, culture or economic status, and instead see each other based on our primary identity: children of God and heirs of God's promise.
Thank You, Father God, for the freedom You brought when You sent Jesus Christ for us. Now we are set us free from the supervision of the law and under the liberating rule of our true king Jesus. Thank You that because in Christ we are all children of God, Jesus gives us reason to look at one another differently, to see one another -- more than anything else -- as children of God and brothers and sisters in Christ. Thank You, Lord, for being my King and giving me my spiritual family!