Believers are first of all Children Of God by adoption. This implies, of course, that they are not Children Of God by nature, as modern liberals would have us believe, for one cannot well adopt his own children. This adoption is a legal act, whereby God places the sinner in the status of a child, but does not change him inwardly any more than parents by the mere act of adoption change the inner life of an adopted child. The change that is effected concerns the relation in which man stands to God. By virtue of their adoption believers are as it were initiated into the very family of God, come under the law of filial obedience, and at the same time become entitled to all the privileges of sonship. The sonship by adoption should be carefully distinguished from the moral sonship of believers, their sonship by regeneration and sanctification. They are not only adopted to be Children Of God, but are also born of God. Naturally these two cannot be separated. They are mentioned together in John 1:12; Rom. 8:15.16; Gal. 3:26,27; 4:5,6. In Rom. 8:15 the term huiothesia (from huios and tithenai) is used, which literally means “placing as a son,” and in classical Greek is always employed to denote an objective placing in the status of a child. The following verse contains the word tekna (from tikto, “to beget”), which designates believers as those who are begotten of God. In John 1:12 the idea of adoption is expressed by the words, “But as many as received Him, to them gave He the right (exousian edoken) to become Children Of God.” The Greek expression here used means “to give legal right.” Immediately thereafter, in the 13th verse, the writer speaks of ethical sonship by regeneration. The connection between the two is clearly brought out in Gal. 4:5,6 . . . “that we might receive the adoption of sons. And because ye are sons (by adoption), God sent forth the Spirit of His Son into our hearts, crying, Abba, Father.” That Spirit regenerates and sanctifies us and prompts us to address God full of confidence as Father.[22]
Dabney also observes the connection between adoption and justification as a legal act and says:
Adoption cannot be said to be a different act of grace from justification. Turrettin devotes only a brief separate discussion to it, and introduces it in the thesis in which he proves that justification is both pardon and acceptance. Owen says that adoption is but a presentation of the blessings bestowed in justification in new phases and relations. And this is evidently correct because adoption performs the same act for us, in Bible representations, which justification does: translates us from under God’s curse into His fatherly favor because its instrument is the same, faith. (Gal. 3:26, with 4:6, 7; Titus 3:7; Heb. 11:7; John 1:12). And because the meritorious ground of adoption is the same with that of justification, viz., the righteous...