David was an interesting guy. He seemed to be humble all through his life, even when king, except that one time. Even when he failed (because he forgot to be humble) he quickly humbled himself before God. He recognized first and foremost that God is the Lord of the universe, nothing compares to Him. David, king and master of the people of Israel calls himself “servant” of God. He knew his place. He had experienced throughout his life the power and majesty of God. David gladly bowed to God as his master.
God is so powerful, so mighty. He is the creator and ruler of the universe. Anything we might lift up as a substitute god, fails miserably. They cannot compare to the might and awesomeness of the Lord God Almighty. We need to acknowledge Him as lord and master of our lives. We need to bow before Him. But we also can look to Him as our provider. He cares for us and will answer our prayers.
There is one more reason to bow to Him as our master. He Himself is our example of how we need to be humble. How we need not only to serve Him but also our brothers and sisters in Christ.
In your relationships with one another, have the same mindset as Christ Jesus: Who, being in very nature God, did not consider equality with God something to be used to his own advantage; rather, he made himself nothing by taking the very nature of a servant, being made in human likeness. And being found in appearance as a man, he humbled himself by becoming obedient to death— even death on a cross! Therefore God exalted him to the highest place and gave him the name that is above every name, that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue acknowledge that Jesus Christ is Lord, to the glory of God the Father. -Philipians 2:5-11