Have you ever noticed that people don't buy cans of paint, open them up, and just leave them sitting in their house? The value of new paint isn't in simply owning the paint – the value comes when it's applied. Sure, these paint cans look pretty, but the real value comes when the colors are applied to the walls. Similarly, God's commands work the same for us. It's not enough to just have His commands in our minds – the value comes to us when we actually apply His commands to our lives. Moses reminded the Israelites of this important truth as they were getting ready to enter into the Promised Land.
The same lesson is important for us. I guess one of my pet peeves is when I hear Christians talk about wanting to have "deep" Bible study but they aren't very interested in applying the knowledge that they already have. We certainly need to study the Scripture, and we need to know God's commands. But we also have to be careful not to elevate knowledge over application. They're both important. If you don't own the paint, then you can't apply it to the wall, but if you don't apply it to the wall, then it's not worth owning. Do you care simply about knowledge? Or are you seeking to live out what you're learning? In this case, the real value comes in the application.