We who are Jews by birth and not ‘Gentile sinners’ know that a man is not justified by observing the law, but by faith in Jesus Christ. So we, too, have put our faith in Christ Jesus that we may be justified by faith in Christ and not by observing the law, because by observing the law no-one will be justified.If, while we seek to be justified in Christ, it becomes evident that we ourselves are sinners, does that mean that Christ promotes sin? Absolutely not! If I rebuild what I destroyed, I prove that I am a law-breaker. For through the law I died to the law so that I might live for God. I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me. I do not set aside the grace of God, for if righteousness could be gained through the law, Christ died for nothing! Gal 2:15-21

This is what makes Christianity unique. We cannot make justify ourselves with God by doing good things, for we are sinners by nature, but God by his grace can make us righteous through faith in Jesus Christ. Hallelujah!