Placed as a son

Adoption in the Bible is a legal act: to place someone in a family as a son, with full rights. Paul says that when you received the Holy Spirit you received "a spirit of adoption", and that Spirit does something in you: it cries, "Abba! Father!" Abba is the everyday Aramaic word a child used for their father at home, grown children as much as small ones. It is not a title. It is the family word. God is not embarrassed by that word. He put it in your mouth.

Look at the chain in Galatians 4. "God sent his Son, born of a woman, born under the law, in order to redeem those who were under the law, so that we might receive adoption as children. And because you are children, God has sent the Spirit of his Son into our hearts, crying, 'Abba! Father!' So you are no longer a slave but a child, and if a child then also an heir through God." The Spirit in you is the proof of the adoption, and the adoption is what makes you an heir.

John says the same more simply. "To all who received him, who believed in his name, he gave power to become children of God, who were born, not of blood or of the will of the flesh or of the will of man, but of God." And then he stops to marvel at it: "See what love the Father has given us, that we should be called children of God, and that is what we are" (1 John 3:1).

A word on the word. This chapter is called "You're His son", and your Bible says "children". Both are right, and it helps to know why. In Galatians 4 and Romans 8:14-15 Paul's word is son, and in his world a son was the one with legal standing in the family: the name, the authority to act for the father, and the inheritance. A slave lived in the same house and had none of those. That is why Paul says "no longer a slave but a child, and if a child then also an heir." John's word is children, born of God, which is about the birth rather than the standing. Your Bible says "children" in Paul's verses so that nobody misses the point that the standing is for everyone. "In Christ Jesus you are all children of God through faith... there is no longer male and female... and if you belong to Christ, then you are Abraham's offspring, heirs according to the promise" (Galatians 3:26-29). Every sister who has been born again is placed as a son in Paul's sense, with the full standing and the full inheritance. Nothing less is on offer.

You did not join a club. You were placed in a family, with a Father who saw you "while he was still far off" and ran (Luke 15:20). The next session is about who that Father is, because you will be asked.