adoption: God's legal placing of those who were not his children into his own family as full sons and heirs.
The Greek word joins "son" and a word for "placing," and it was the ordinary term for legal adoption in Paul's world. It turns up constantly in ancient inscriptions and adoption papers, where adoption was chiefly a way to secure a full heir: it conferred a new name, complete inheritance rights, and standing equal to a child born in the house. Careful study of every ancient use has settled a long argument: the word always names the act of adopting someone in, never merely the state of already being a son.
Paul is the only writer in the New Testament to use it, and always for something God does. His five uses fit together into one picture:
- Israel's own adoption as God's people stands at the root (Romans 9:4).
- Believers are placed into God's family now, a standing sealed by the Spirit (Romans 8:15; Galatians 4:5).
- That placing was planned before the world was made (Ephesians 1:5).
- Its full, public unveiling still waits for the resurrection of the body (Romans 8:23).
Because the word is a legal picture rather than a birth, it says something that being a born child (τέκνον) or simply a son (υἱός) does not: people who were outsiders, even slaves, are deliberately brought inside and made full heirs (κληρονόμος) by sheer grace. Scholars still debate which world Paul leans on most, Roman adoption law or Israel's covenant, but the common ground is that he takes a Greek legal word and fills it with the Old Testament promise that God would be a Father to his people.
Nuances
Disputed
Which cultural world Paul primarily draws on when he calls salvation "adoption": Roman law, Israel's covenant, or Roman imperial succession.
- majorityAn integrative reading: Paul uses a Hellenistic legal word and fills it with Old Testament covenantal content (Israel as firstborn son, the Davidic king as adopted son), realized in Christ and the Spirit; the Roman-versus-Jewish question is a false dichotomy.; Trevor J. Burke, Adopted into God's Family (NSBT 22; IVP/Apollos, 2006); Erin M. Heim, Adoption in Galatians and Romans (BINS 153; Brill, 2017); Michael Peppard, The Son of God in the Roman World (Oxford, 2011)
- minorityThe primary background is the Roman legal institution of adoptio and adrogatio: transfer to a new father, cancellation of former obligations, a new name, and full inheritance rights.; Francis Lyall, "Roman Law in the Writings of Paul: Adoption," JBL 88 (1969): 458-66; Harold W. Hoehner, Ephesians (Baker, 2002)
- minorityThe metaphor is essentially Jewish though the word is Greek: grounded in Israel's covenantal sonship (Exodus 4:22; 2 Samuel 7:14) and read through a New Exodus typology.; Brendan Byrne, "Sons of God" - "Seed of Abraham" (AnBib 83; Biblical Institute Press, 1979); James M. Scott, Adoption as Sons of God (WUNT 2/48; Mohr Siebeck, 1992)