Paul here explains one of the primary ways in which Jesus fulfilled the law. Romans 7:1-6

Don’t you realize, brothers—for I am speaking to people who know the law—that the law can press its claims over a person only as long as he is alive? For a married woman is bound by the law to her husband while he is living, but if her husband dies, she is released from the law concerning her husband. So while her husband is living, she will be called an adulterer even if she lives with another man. But if her husband dies, she is free from this law, so that she is not an adulterer if she marries another man. In the same way, my brothers, through Christ’s body you also died as far as the law is concerned, so that you may belong to another person, the one who was raised from the dead, and may bear fruit for God. For while we were living in the flesh, sinful passions aroused by the law were at work in our bodies to bear fruit for death. But now we have been released from the law by dying to what enslaved us, so that we may serve in the new life of the Spirit, not under the old written code.

The brutal truth of God’s standard as expressed in the written code is that the law requires death for all transgressors. Paul has thus far argued for seven chapters that all people are transgressors and thus all are deserving of death - the kind of death that separates us from God forever. This chapter is interesting because Paul appears to be speaking of the law in quite a negative fashion. He states that the law arouses sinful passions, and that the result of this is death. This simply reveals the truth that because of our sinful nature, when we hear a command, we are automatically tempted to break that command. Man has always desired to break his boundaries, and this is still the case. Therefore, a law in and of itself cannot save man, because that law will only cause transgression. Consequently this transgression only results in death.

However, the wonderful part of the story is that though Jesus did not come to abolish the law, He came to fulfill it. I think that Paul here is explaining a fundamental way in which Jesus fulfills the law. Another way is by living the law perfectly, as Jesus never sinned, but here Paul is getting at the opposite of living - dying. Since the lawn requires death for sin, Jesus fulfills the law by dying as a substitute for whoever God elects to believe in the substitute. Therefore, the one who has faith and follows Christ experiences this fulfillment first hand. Christians are still deserving of this requirement of the law - death. However, Jesus fulfills it for them.

Paul’s application of this to the idea of marriage is interesting. There is no way for a marriage to be separated. Thus, while both marriage partners are alive, the law binds them to each other. The only instance where these two individuals are considered released from what God has joined together is if one of them dies. It is the same with the law’s requirement of death for sinners. God’s standard as revealed in the law requires death for transgressors. We can never be free from this requirement, and God cannot simply absolve this requirement. The only way for us to be released from the law is if someone fulfills the requirement for us, and that is exactly what Jesus has done. He has fulfilled the positive requirement of the law by living a perfectly righteous life, and He has fulfilled the negative requirement of the law by dying on behalf of the church.

Now, practically, what does this mean? Jesus has much to say about how we should still follow the law and obey the commandments in the sermon on the mount. Is Paul at odds with Jesus? I don’t think so, because Paul is merely talking about the law’s requirement of death. When sinner is made into an heir - as Paul will argue in ch. 8 - then the “law of the spirit of life” does exactly the opposite of what the written law does. The written law arouses the desire to break the law, but the “law of the spirit of life” drives us to obedience. And, what should we desire to obey? The written standard, though we never think that obedience to the standard will save us, because we are already saved. The application of this is difficult, but Jesus does it beautifully in the sermon on the mount (Matthew 5-7). We are free from the law’s requirement of death, and we are therefore free to obey the law with a new heart.