We have been united with Christ to live for Him in this life and with Him in our death.
Paul is showing what and why those who are saved by faith through grace will walk in obedience. Our motivation to walk in obedience is Christ in us, and the overflow of God dwelling in us results in obedience and love for God. Obedience is not a matter of making God love us, it reflects our love for God and us being united with God.
Christ must be the center of Christianity. You will find joy when you say I am not enough, God is.
You are united with Jesus so live like it. You are destined for glory, so live like it.