1 “Or do you not know, brothers and sisters (for I am speaking to those who know the Law), that the Law has jurisdiction over a person as long as he lives? 2 For the married woman is bound by law to her husband as long as he is alive; but if her husband dies, she is released from the law concerning the husband. 3 So then, if while her husband is alive she gives herself to another man, she will be called an adulteress; but if her husband dies, she is free from the law, so that she is not an adulteress if she gives herself to another man.” 4 Therefore, my brothers and sisters, you also were put to death in regard to the Law through the body of Christ, so that you might belong to another, to Him who was raised from the dead, in order that we might bear fruit for God. 5 For while we were in the flesh, the sinful passions, which were brought to light by the Law, were at work in the parts of our body to bear fruit for death. 6 But now we have been released from the Law, having died to that by which we were bound, so that we serve in newness of the Spirit and not in oldness of the letter.”
Paul is using marriage to make an important point: Just as you can’t be married to two people you can’t be married to both Jesus and the law. Believers have died to the law through the body of Christ. We are now married to Jesus, a stark contrast to the law. We are no longer trying to imitate external principles. We are not even trying to imitate a religious teacher who lived 2000 years ago (sorry, no W.W.J.D. here). Instead, we are living out of our union with Jesus. To mix law and Jesus is to commit spiritual adultery.
Brought to light by the Law: The law did nothing to curb sinful desires. To the contrary, it excited sin. When we mix law and Jesus, we are inviting ourselves into a life of sinful failure. Instead, we are to express the fruit of the Spirit that Jesus is producing within us daily (see Galatians 5:22-23). This is what it means to serve in newness of the Spirit.