This is the original request Moses made to Pharaoh for Israel to be set free. The reason was that they might be free to sacrifice to their God. The same principle applies to us; this is why God has freed us. Recall that Romans 12:1 charges us with the responsibility, once we are free of our slavery to Satan and sin, to be living sacrifices.
The blessing of our God-given calling makes available to us the opportunity to dedicate our lives in service to Him. Its magnificent potential opens the door to positive motivation to counterbalance the somewhat negative sense that obligation to Christ seems to impose. Because He first gives us evidence of His love for us, it enables us to believe Him, to live by faith, and to live a life of self-sacrifice to glorify Him. It has provided entrance to the Kingdom of God.
The just shall live by faith because they know Him in His loving character. This causes any lingering negative sense that human nature has toward being required to keep God's commands to fade gradually into the background, freeing us to obey from the heart in sincere gratitude and joy.
John W. Ritenbaugh
A Priceless Gift