We start out as slaves. Our path to maturity starts with servitude and obedience. I saw this in my relationship with my father. I had to learn obedience first. When I matured, we became the closest of friends. He treated me that way and I responded. That was so cool.
The same is true with our heavenly Father. We are his friends. He tells us His most innermost feelings and secrets. God wants us to have a heart after Him and wants us to live in intimacy with Him. He wants this far and away above obedience.
God wants us to mature. He wants us to move beyond servitude. He wants us to be His friend. He wants us to co-reign with the Messiah Jesus.