Paul explains what the Gospel is in the book of Romans - that we have been made right with God through the work of Christ. A relationship with God has been made possible through the reconciling work of the Jesus. But, how are we now related to God? What are we to God, and what is He to us? This passage presents the astonishing truth that we are not merely subjects to a King, or slaves/servants to a master, or devotees to a god. We are in fact adopted – made sons of God with all the rights, privileges, and duties that come with being His children! Being adopted defines the nature of our relationship, the role we play in the Kingdom, the rights that are ours, and our duties and obligations.
