Paul's marriage analogy illustrates how believers have died to the Mosaic law through Christ's body, freeing them to bear fruit for God rather than sin. His personal struggle with sin in verses 14-25 demonstrates the law's inability to produce the righteousness it demands while revealing the internal conflict that characterizes even mature believers. The cry "Wretched man that I am! Who will deliver me?" sets up chapter 8's answer about life in the Spirit overcoming the law's weakness.