What does adoption mean in the Bible?A Scripture-grounded answer about adoption in the bible

Adoption (huiothesia in Greek) is the act by which God brings believers into his family as sons and daughters with full rights and privileges. In the Roman world, adoption gave the adopted child the same legal status as a biological child — including inheritance rights. Paul uses this legal metaphor to describe what happens at salvation: believers receive the 'Spirit of adoption' who enables them to cry 'Abba, Father.' Adoption is distinct from regeneration (new birth): regeneration gives new nature, adoption gives new status and family membership.