You asked

how did the roman audience understand the concept of 'adoption' in their social context?

The passage, plainly, with room to sit with it.

Romans 8:15-17

“For you didn’t receive the spirit of bondage again to fear, but you received the Spirit of adoption, by whom we cry, “Abba! Father!” The Spirit himself testifies with our spirit that we are children of God; and if children, then heirs; heirs of God, and joint heirs with Christ; if indeed we suffer with him, that we may also be glorified with him.”

The Apostle Paul is writing to Christians in Rome, a diverse city with both Jewish and Gentile believers. In this section of his letter, Paul is explaining the transformative power of the Holy Spirit in the lives of believers, moving them from a state of fear and bondage under the law to one of freedom and intimate relationship with God.

What does it mean for your life today to understand yourself as adopted into a new family, with all its rights and responsibilities?

Keep thinking

Read alongside it

Galatians 4:4-7
This passage similarly speaks of being adopted as sons and receiving the Spirit, calling God 'Abba, Father'.
Ephesians 1:5
It states that God 'predestined us for adoption to himself as sons through Jesus Christ, according to the purpose of his will'.
John 1:12-13
This describes those who believe in Jesus receiving the right to become children of God, not by natural birth but by God's will.

Ask your own follow-up