What's the connection between functioning as a servant of God and hoping in the inheritance as a son of God?  

Fr. Paul Hodge remembers the aphorism of Fr. Thomas Hopko of blessed memory, "Beware of consolation before the crucifixion." Like a child who wants dessert before dinner, we may want all of the glory of God's promises now.  Looking to Romans 8, we are reminded of the order and the responsibility to receiving God's gift.  Sharing in the inheritance as sons comes after suffering with Christ, and not before.