Adoption

Exodus 2:10; Esther 2:7; Exodus 4:22; Deuteronomy 14:1; Isaiah 43:6; Romans 9:4; Galatians 4:5-6; Romans 8:15-23; Ephesians 1:4-5
The word is υιοθεσἰα, the adoption of sons, or the placing of persons in the position of sons, with all the privileges attaching thereto. Examples of this in a natural way are seen in the Old Testament in Moses being an adopted son of the daughter of Pharaoh (Ex. 2:1010And the child grew, and she brought him unto Pharaoh's daughter, and he became her son. And she called his name Moses: and she said, Because I drew him out of the water. (Exodus 2:10)), and Esther being adopted by her cousin Mordecai (Esther 2:77And he brought up Hadassah, that is, Esther, his uncle's daughter: for she had neither father nor mother, and the maid was fair and beautiful; whom Mordecai, when her father and mother were dead, took for his own daughter. (Esther 2:7)). In a higher sense, Israel was the adopted son of God. Moses was instructed to say to Pharaoh, “Thus saith Jehovah, Israel is my son, even my firstborn” (Ex. 4:2222And thou shalt say unto Pharaoh, Thus saith the Lord, Israel is my son, even my firstborn: (Exodus 4:22); compare also Deut. 14:11Ye are the children of the Lord your God: ye shall not cut yourselves, nor make any baldness between your eyes for the dead. (Deuteronomy 14:1); Isa. 43:66I will say to the north, Give up; and to the south, Keep not back: bring my sons from far, and my daughters from the ends of the earth; (Isaiah 43:6)). So that Paul, when enumerating the privileges of Israel, could say that to them pertained the adoption (Rom. 9:44Who are Israelites; to whom pertaineth the adoption, and the glory, and the covenants, and the giving of the law, and the service of God, and the promises; (Romans 9:4)). In a much higher sense, since redemption has been wrought, those who believe in the Lord Jesus Christ are in the new creation sons by adoption, and the Spirit of God’s Son is given them so that they can call God, Abba Father, and not only be sons but know and enjoy the relationship with all its blessed privileges (Gal. 4:5-65To redeem them that were under the law, that we might receive the adoption of sons. 6And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father. (Galatians 4:5‑6)). The Christian receives the spirit of adoption, the Holy Ghost bearing witness with his spirit that he is a child of God. Not that he enters into the full blessedness of being God’s son until the future; for we who have the first-fruits of the Spirit groan within ourselves waiting for the adoption — the redemption of our body (Rom. 8:15-2315For ye have not received the spirit of bondage again to fear; but ye have received the Spirit of adoption, whereby we cry, Abba, Father. 16The Spirit itself beareth witness with our spirit, that we are the children of God: 17And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together. 18For I reckon that the sufferings of this present time are not worthy to be compared with the glory which shall be revealed in us. 19For the earnest expectation of the creature waiteth for the manifestation of the sons of God. 20For the creature was made subject to vanity, not willingly, but by reason of him who hath subjected the same in hope, 21Because the creature itself also shall be delivered from the bondage of corruption into the glorious liberty of the children of God. 22For we know that the whole creation groaneth and travaileth in pain together until now. 23And not only they, but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, to wit, the redemption of our body. (Romans 8:15‑23)). All this is certain as to believers, for having been chosen in Christ Jesus they have been predestinated unto adoption by Jesus Christ to Himself according to the good pleasure of His will (Eph. 1:4-54According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love: 5Having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will, (Ephesians 1:4‑5)).