In this series, we have been looking at what God’s Word says about adoption as both an earthly call to care for orphans and as a picture of how He saves undeserving sinners in need of a right relationship with Him. You can read Parts I , II, III, IV, V, and VI here. In this article, we see how what the Bible teaches about the doctrine of adoption.
As I explained in previous articles, Millard Erickson gives us a helpful process of doing theology by starting with exegesis (interpreting the Biblical texts), moving on to biblical theology (the through-line of Scripture), and then systematic theology (specific doctrines). We have already taken the first step (exegesis) of interpreting some passages from the Old and New Testaments that deal with God’s concern for the fatherless and how he adopts believers as his forever children. In the previous article, we saw how the doctrine of adoption fits into the Bible as a whole by means of the discipline of Biblical Theology. Now we will survey what various systematic theologians have had to say about the doctrine of adoption.
What is Systematic Theology?
There are some professing Christians who say they “don’t need theology,” they “just want Jesus.” The problem with that approach is that you cannot talk about Jesus without getting into theology. Who is Jesus? If Jesus is our “Savior”, then what exactly are we being saved from? If we tell people to “Give your life to Christ.”, what does that actually mean? Why should they? Any answers to these questions will unavoidably be theological. R.C. Sproul was exactly right when he said that we are all theologians. The question is whether we will be good ones or bad ones. So what is theology? Though related to religion, it is not the same thing as religion. Theology is the study of God himself. Systematic Theology is the process of seeking thoroughly and methodically to know God as he has revealed himself. No, we should never try to “put God in a box.” At the same time, we should never try to put God in a blender.
Adoption and Systematic Theology
Systematic theologians have offered various perspectives on how adoption should be understood in relation to justification. Is adoption just another way of describing justification? If adoption is distinct from justification, how are they related? How does adoption relate to regeneration? Or sanctification?
Modern Calvinistic Baptists have given some attention to adoption in systematic theology. Millard Erickson categorizes adoption as an objective aspect of salvation along with union with Christ and justification. In his estimation, adoption means a change in status from alienation and hostility before God to one in which the believer enjoys God’s acceptance and favor. God’s adopted children receive the benefits of his eternal forgiveness, reconciliation, liberty, and fatherly care. Rather than liberty and care as a license to sin, the adopted child of God serve him out of obedience and experience his fatherly discipline. Wayne Grudem gave adoption its own chapter, distinguishing the doctrine from regeneration and justification which also warrant their own chapters. Adoption is recognized as distinct from justification, in that God could have conceivably justified sinners without ever adopting them into his family.
Theologians from the Reformed Paedo-Baptist tradition have provided extensive insights into adoption. Louis Berkhof reasoned that men are not children of God by nature since one does not typically adopt his own children. Berkhof placed adoption along with the right to eternal life as falling under the category of positive elements of justification. While Berkhof recognized adoption as a legal but distinctively relational change of status before God, I think his choice to make adoption a subtopic of justification demonstrated an insufficient appreciation for the uniqueness of the doctrine.
In the more recent past, Robert Reymond saw adoption as a particular benefit of the “cross work of Christ”, connected to but distinctive from union with Christ, justification, and sanctification. The believer’s newly granted relationship to God as heavenly Father warrants adoption’s distinctiveness. For Michael Horton, justification and adoption are both to be seen as aspects of the believer’s union with Christ. John Frame, in keeping with his tri-perspectival method, looked at adoption in relation to justification and what he terms “subjective salvation” which includes regeneration, conversion, and sanctification. He distinguishes justification and adoption, noting how the justification relates to a new legal standing before God and the adoption means to be granted an inheritance. Justification is a declaration of imputed righteousness from God as judge, while adoption is a declaration of derived sonship from God as heavenly Father. In 2019 we got a new Systematic Theology from Robert Letham. He did not neglect to include adoption, offering a brief but helpful section on the doctrine. He rightly points out that through redemption believers we are delivered but without adoption, we would not know what we are delivered to.
Systematic theology helps us to see the doctrine of adoption in proper relation to other aspects of soteriology (the study of salvation) like justification. Through union with Christ, believers receive the benefits of adoption. This newfound status of sonship is unmerited by the believer and must be accomplished by an act of God’s loving initiative. On a pastoral level, when justification, adoption, and regeneration are clearly understood in relation to one another, the believer’s assurance of salvation is strengthened.
If you have never turned from your sin and looked to Jesus Christ as your Savior, do it now. He lived the perfect life as the true and better Adam, took the punishment we all deserve, died on a Roman cross, and rose again on the third day. God the Father is drawing sinners to himself by the power of God the Spirit. God not only forgives sinners based on the work of Christ, but He also adopts them into his forever family out of pure grace.
In future articles, we will take a closer look at what the Puritans, the early Baptists, and others can teach us about adoption. If you have questions, comments, or requests for other topics, please feel free to contact me or leave us a comment below.
 Millard J. Erickson, Christian Theology, 3rd ed. (Grand Rapids: Baker Academic, 2013), 53-65.
 R.C. Sproul, Everyone’s a Theologian: An Introduction to Systematic Theology (Sanford: Reformation Trust), 12.
 Erickson, Christian Theology, 3rd ed., 8-9.
 I’m avoiding the term “Reformed Baptist” for technical reasons in addition to not wanting to trigger the Truly Reformed.
 Ibid., 876-895.
 Ibid., 891.
 Ibid., 893-894.
 Wayne Grudem, Systematic Theology: An Introduction to Biblical Doctrine. (Grand Rapids: Zondervan, 1994), 736-745.
 Ibid., 739.
 Louis Berkhof, Systematic Theology. (Carlisle: Banner of Truth Trust, reprinted 2012), 515-516.
 Robert L. Reymond, A New Systematic Theology of the Christian Faith. Rev. and updated ed. (Nashville: Thomas Nelson, 1998), 759-762.
 Ibid., 759.
 Michael Horton, The Christian Faith: A Systematic Theology for Pilgrims On the Way (Grand Rapids: Zondervan, 2011), 642-645.
 John M. Frame, Systematic Theology: An Introduction to Christian Belief (Phillipsburg: P&R Publishing, 2013), 964-982.
 Ibid., 977.
 Robert Letham, Systematic Theology (Wheaton: Crossway, 2019), 732.
 Matthew Barrett, “Raised for Our Justification: The Christological, Covenantal, Forensic, and Eschatological Contours of an Ambiguous Relationship”, in The Doctrine on Which the Church Stands or Falls: Justification, in Biblical, Theological, Historical, and Pastoral Perspective. ed. Matthew Barrett. (Wheaton: Crossway, 2019), 413. Constantine R. Campbell, Paul and Union with Christ: An Exegetical and Theological Study (Grand Rapids: Zondervan, 2012), 247. David B. Garner, Sons in the Son: The Riches and Reach of Adoption in Christ. (Phillipsburg: P&R Publishing, 2016), 254-286. Michael Horton, New Studies in Dogmatics. Justification, Volume 1 (Grand Rapids: Zondervan, 2018), 366. Horton, Justification, Volume 2, 465.
 Robert Alexander Webb. The Reformed Doctrine of Adoption (Harrisonburg: Sprinkle Publications, 2012), 126-147.
 Sinclair B. Ferguson, The Whole Christ: Legalism, Antinomianism, & Gospel Assurance – Why the Marrow Controversy Still Matters (Wheaton: Crossway, 2016), 199. Ferguson extends this concern for assurance in relation to the doctrine of particular redemption in “Blessed Assurance, Jesus is Mine”, in From Heaven He Came and Sought Her: Definite Atonement in Historical, Biblical, Theological, and Pastoral Perspective. ed., David Gibson and Jonathan Gibson. (Wheaton: Crossway, 2013), 617.