Laws are stated and have penalties. Rulers enforce them, but that does not stop people from breaking them—in many cases with impunity—especially if they feel no government representative is watching them. The government's power lies largely in coercion, meaning forcible constraint or restraint, whether moral or physical. In other words, it is government by force.
For instance, most people flagrantly disobey the speed limit on freeways and interstates, especially when they are not crowded, until they spot a patrol car with a trooper or two in it. Suddenly, the speed limit becomes the norm until the trooper is again out of sight. That the law is on the books, prominently displayed and common knowledge are insufficient motivation for many people to obey.
But love toward God, the love of God, can motivate us to do what the law says to do but cannot motivate us to do. We can conclude that Paul claims that if one exercises God's love in paying his debt to man, he will keep the commandments.
We could also conclude that Paul says that if one does not break the commandments, he is acting out of love. This is the weaker of the two. Within this context, then, every phase, every facet of our responsibility to God and man, is covered if we make sure love has its place as the motivation for all we do.
If we really love another person, we cannot possibly injure him. Love would immediately stifle any thought that leads to adultery, murder, theft, or any form of covetousness because love cannot harm. Since love cannot break the laws designed to protect another, it is supreme in providing the right kind of persuasion.