Law
When a slave failed to please his master, there were severe and fearful consequences that had to be endured. However, a slave had one hope and one secuairty; perform his duties with perfection. When the master specified in detail all of his duties and the slave fulfilled them, he could feel some security and acceptance. It was a security through accomplishment and perfectionism, but the sense of security was always overshadowed by his fears of inadequacy. The slave could perform his service with no love, admiration, or oneness of purpose with his master. That is a spirit of bondage.
Grace
A Son serves his father out of a sense of belonging, acceptance, love, and unity of purpose with the father. The son knows that his security and acceptance are dependent upon his relationship with his father rather than his ability and diligence to achieve. His hope, confidence, and security is in the unconditional love of his father. His service and obedience is in gratitude for the father's love and sustenance rather than to meet demands of specifics and quotas set by the father. A young man is free from the fears of inadequacy of performance and he is free to exercise himself creatively in a loving relationship expressed by love and joy that results in the perfection and abilities that honor his father. This is the spirit of freedom that sons may enjoy.