A Hebrew servant had to serve his master for six years. In the seventh he could go out free. But if the servant said, "I love you, master, and I want to continue serving you," then the master took the servant to the front door, put his ear against the doorpost and with an awl pierced his lobe. Now he is no longer just a servant, but the servant has access to the house and part of the master's family.
You can serve the Lord out of duty, like the servant did, or you can go beyond that into a love relationship with the Master.
