There are two motivations or orientations to consciously living out our faith. The first way is living as a slave which results in our being afraid of God. This is not necessarily far off the mark as the Apostle Paul does speak of us as being slaves of righteousness in Romans 6. Paul himself is a slave of Christ as he opens the book of Romans. However, the other way to live out the call of the Gospel is as a son. Why would Paul make a distinction between sonship and slavery if he identifies himself as a slave of Christ?