Romans 7:1-6 // The Law Where There Is No Law

Know ye not, brethren, (for I speak to them that know the law,) how that the law hath dominion over a man as long as he liveth? 2 For the woman which hath an husband is bound by the law to her husband so long as he liveth; but if the husband be dead, she is loosed from the law of her husband. 3 So then if, while her husband liveth, she be married to another man, she shall be called an adulteress: but if her husband be dead, she is free from that law; so that she is no adulteress, though she be married to another man. 4 Wherefore, my brethren, ye also are become dead to the law by the body of Christ; that ye should be married to another, even to him who is raised from the dead, that we should bring forth fruit unto God. 5 For when we were in the flesh, the motions of sins, which were by the law, did work in our members to bring forth fruit unto death. 6 But now we are delivered from the law, that being dead wherein we were held; that we should serve in newness of spirit, and not in the oldness of the letter. (Romans 7:1-6)

The law cannot touch a dead man. When there is a plane crash and many people die, usually the pilot (who is also dead) is concluded to be at fault. Even though the law cannot touch him personally it is still used to condemn (show his guilt) or vindicate him (show his innocence). The result is relevant to his family who want to remember him as a good man, they want him to be found to be innocent. So the law is still relevant to dead men, but the point Paul is making here is that the law cannot touch him personally because he is already dead. He uses the example of widowhood and remarriage, saying that the husband being dead makes all the difference in this case.
Paul says that this is a similar idea to how we need to live our faith. It's like you have died, your "old life" is gone, the acquaintances that dragged you down, the habits that you couldn't break, the frustrations that wouldn't go away. In their place you have Jesus who will give you love, freedom and peace.
Then Paul goes on to say something a little complicated about the law, which I'm not entirely sure about. This is the sense I make of it:
Before you were converted you were doing things that you knew were wrong (and the fact they were against the law was how you knew), you knew about right and wrong and chose to do wrong and knew you were guilty of death and much of what you did just brought death closer. But now Jesus has forgiven you for breaking the law and given you power to keep it so you have no problem with the law since your law-breaking that condemned you is now over. This power allows you to know God personally and obey him intuitively based on a thorough understanding of who he is and what he wants rather than by studying the details of the law and basing your system of morality entirely on the very specific things that he required and forbade the Hebrews thousands of years ago.

Some of us find it tempting to look for clear rules to follow. Jesus gives some rules and we should follow them, but there is much more to following Jesus than this. To really follow Jesus we must think about what he wants and do it without needing to be commanded. Acts of selfless service to others and witnessing are too complex to specifically mandate but Jesus wants us to do these things.