The taking or accepting as a son or daughter one who is not such by natural relationship. The Greek word translated “adoption as sons” (hui·o·the·siʹa) is a technical legal term that literally means “a placing as son.”—Compare Ro 8:15, ftn.
In the Hebrew Scriptures adoption is not dealt with from the viewpoint of legal procedure, but the basic idea is set forth in several cases. It appears that Abraham, prior to the birth of Ishmael and Isaac, considered his slave Eliezer as at least in line for a position similar to that of an adopted son and as the likely inheritor of Abraham’s house. (Ge 15:2-4) The practice of adopting slaves as sons has long been a common Middle Eastern practice, and as such they had inheritance rights, though not above those of children descended naturally from the father.
Rachel and Leah both considered the children born to Jacob by their handmaids as their own sons, ‘born upon their knees.’ (Ge 30:3-8, 12, 13, 24) These children inherited along with those born directly of Jacob’s legal wives. They were natural sons of the father, and since the slave girls were property of the wives, Rachel and Leah had property rights in these children.
The child Moses was later adopted by Pharaoh’s daughter. (Ex 2:5-10) Since men and women had equal rights under Egyptian law, Pharaoh’s daughter was in position to exercise the right of adoption.
Within the nation of Israel adoption does not appear to have been widely practiced. The law of levirate marriage doubtless eliminated to a great extent a basic reason for adoption of children: the continuance of the parental name.—De 25:5, 6.
A Christian Significance. In the Christian Greek Scriptures adoption is mentioned several times by the apostle Paul with regard to the new status of those called and chosen by God. Such ones, born as descendants of the imperfect Adam, were in slavery to sin and did not possess inherent sonship of God. Through purchase by means of Christ Jesus, they receive the adoption as sons and also become heirs with Christ, the only-begotten Son of God. (Ga 4:1-7; Ro 8:14-17) They do not come by such sonship naturally but by God’s choice and according to his will. (Eph 1:5) While acknowledged as God’s children, or sons, from the time of God’s begetting them by his spirit (1Jo 3:1; Joh 1:12, 13), their full realization of this privilege as spirit sons of God is dependent on their ultimate faithfulness. (Ro 8:17; Re 21:7) Thus, Paul speaks of them as “earnestly waiting for adoption as sons, the release from our bodies by ransom.”—Ro 8:23.
Such adopted state brings benefits of freedom from “a spirit of slavery causing fear,” replacing it with the confidence of sons; of hope of a heavenly inheritance assured by the witness of God’s spirit. At the same time these spiritual sons are reminded by their adoption that such position is by God’s undeserved kindness and selection rather than by their inherent right.—Ro 8:15, 16; Ga 4:5-7.
At Romans 9:4 Paul speaks of the fleshly Israelites as those “to whom belong the adoption as sons and the glory and the covenants and the giving of the Law,” and this evidently refers to the unique position granted Israel while they were God’s covenant people. Thus, God, on occasion, spoke of Israel as “my son.” (Ex 4:22, 23; De 14:1, 2; Isa 43:6; Jer 31:9; Ho 1:10; 11:1; compare Joh 8:41.) Actual sonship, however, awaited the ransom provision made through Christ Jesus and was dependent on acceptance of that divine arrangement and faith in it.—Joh 1:12, 13; Ga 4:4, 5; 2Co 6:16-18.