"So, my brothers, you also died to the law through the body of Christ, that you might belong to another, to him who was raised from the dead, in order that we might bear fruit to God." -- Romans 7:4
The law was given to reveal the inability of man to fulfill his obligation to God. It was never meant to save his soul or enable him to bear spiritual fruit. In Christ we not only died to sin, but we also died to the law. Now we belong to the One who rose from the dead in order that we might bear fruit to God. The obligation has ceased and the romance has begun. The difference is a relationship.
Think about this: "Christian obedience is unlike every other kind of obedience. It is not the obedience of slaves or soldiers, but essentially the obedience of lovers who know, love and trust the person who issues the commands." ~ John R. W. Stott