In Galatians 1, Paul reminds the church at Galatia that there is one gospel, one real, eternal truth- Jesus Christ is Lord and it is by His grace, through faith, we receive salvation. Though the church received the gospel initially, certain men had come preaching a different way and confused many. The false-teachers sought for all Christians to be bound under the Mosaic law. The church at Galatia quickly forsook the gospel of grace and began to reject the apostleship of Paul. Honestly, this makes sense. It's much easier to keep a list of "do's and don'ts," than to give your heart over to God. The Law gives us credit, the gospel gives us Christ. The Law makes us feel good (or bad) about ourselves, the gospel shows us who we really are in Christ. The Law obsesses over making an old life better, the gospel says we are new creations in Christ. The Law is striving, the gospel is forgiveness in Christ.
We ourselves are Jews by birth and not Gentile sinners; yet we know that a person is not justified by works of the law but through faith in Jesus Christ, so we also have believed in Christ Jesus, in order to be justified by faith in Christ and not by works of the law, because by works of the law no one will be justified. -Galatians 2:15-16
By the works of the law no one will be justified. By faith in Christ, through the grace of God, everyone, anyone, can be justified. Not that sin should abound, but so that His love would be our acceptance and the motive for obedience. Just like any lover, God wants your heart, your trust in His authority, your respect and your affection. That kind of relationship and intimacy begins with finding your acceptance in the justification of Christ. The Law (works, self-righteousness, perfectionism, "good deeds"), produces fear. Fear of failing, fear of being left alone, fear of your mistakes, fear of what others will think, and on and on... But there is no fear in love, in Christ.
So then, the law was our guardian until Christ came, in order that we might be justified by faith. But now that faith has come, we are no longer under a guardian, for in Christ Jesus you are all sons of God, through faith. -Galatians 3:24-26