The three most important words for the Christian life begin with a “G.” They are guilt, grace, and gratitude, and they're words you should know.
The Law of God exposes our guilt, and it shows us where exactly we have broken God’s commandments (Rom. 3:20). Without hearing the Law, we will continue to go on in our lives thinking that we’re doing just fine. We will inevitably create standards (a.k.a. “laws”) by which we can live and others will never really measure up to—avoiding the reality that all of us have fallen short of the glory of God. We need to hear a message of guilt, so that we will wake up to the message of grace.
The Gospel of God is all about God’s grace to lawbreakers (Rom. 3:21–25). In his Son, God has taken upon himself the judgment and punishment we deserved for breaking the law, and he has also perfectly obeyed all of the law for us. Jesus Christ measured up so we wouldn’t have to. The message of grace is what God has done for us—not what we can do for God.
Our only response to hearing this message of grace is heartfelt gratitude to God and loving service to our neighbors (Eph. 2:10; John 15:5). When someone gives us a gift that we weren’t expecting, our usual response is gratitude. The gospel does this to us a hundredfold and causes us to rejoice and praise God (Rom. 11:33)! We are filled with faith, hope, and love; and even good works spill over onto others because of this great work that God has done for us—and is doing in us.