In Matthew 5, Jesus says “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished.” (Matt. 5:17-18). Jesus doesn’t abolish or nullify the commandments. Neither does He come to simply reiterate them. Instead, he “fulfills” them. He keeps them. He accomplishes them. Jesus obeys the entire law. He is God, the law is God’s will, so the law is Jesus’ will.
In 1 Corinthians 2, St. Paul says, “For I decided to know nothing among you except Jesus Christ and him crucified” (1 Cor. 2:2). The content of Paul’s preaching and teaching to the Corinthians is Christ’s death to save us sinners. That’s the Gospel.
The question is, how are these two truths related? Jesus kept the law. In baptism the victory He won over sin and death on the cross is given to you. You are counted as righteous before God on account of faith in the promises of Christ. How then does the law fit in to the Christian life? Remember, Jesus didn’t abolish the law. He fulfilled it. He kept it. He was righteous. So, if Jesus kept the law, and you are clothed with His righteousness, then in the sight of God you have kept the law. You have fulfilled the law. You are counted, like Jesus, as righteous.
The law is not abolished, but our relationship to the law is no longer one of fear or terror. The eternal punishments that come from violating God’s law are rendered null and void for the Christian, because we possess Christ’s righteousness. As Christians, citizens of Christ’s kingdom, our desire is to keep God’s law, to follow His will. Why? Because we know it is good for us. We know God gives us the law for our own good and the good of our neighbor. Our loving Father wants us to promote good and oppose evil. Good works do not save us, yet they are a necessary to the Christian life, and through the power of God's Spirit we do them. Thanks be to God that Jesus has fulfilled the law, given us His righteousness, and stirred up in us the desire to do good.