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 right relationship with Him. You can read Parts I , II, and III here. In this article, we see how the New Testament writers, under the inspiration of the Holy Spirit, looked at spiritual adoption.
Adoption in the Gospel of John
The Gospel According to John is recognized as one of the most theologically rich books of the Bible. John writes that God the Father sends the Son to be the true light who gives light to everyone (cf. John 1:9). Those who receive the Son are given the incredible right to become the children of God (cf. John 1:12). The status of sonship is granted immediately and yet the believer “becomes” the child of God through a gradual appreciation and fuller sense of the implications of this reality. Caiaphas said more than he realized when he was used as God’s mouthpiece and prophesied that the death of Jesus would bring salvation to “the nation” as well as the gathering of God’s scattered children (cf. John 11:49-52).
Adoption in Paul’s Letters
The apostle Paul, as God’s instrument called by the risen Christ, provides the clearest teaching on God as adoptive Father to His people. Paul employs the unique Greek word huiothesia to refer to adoption by God of a son. This is not a sexist neglect of women. Remember, the New Testament writers had no problem calling the church, made up of men and women, the “bride” of Christ. In that cultural context, it was the son of a family that was entitled to the inheritance and privileges of that family. In other words, Paul is saying that the redeemed men and women of the church have been adopted into God’s family and all of them receive the benefits and privileges granted to them as “sons” of God.
Beginning with his letter to the Romans, Paul encourages believers to live by the Spirit as adopted sons of God, no longer in bondage to the deadly sins of the flesh (cf. Romans 8:15-23). As with Caiaphas’s unintentionally profound words about the gathered and scattered children of God, Paul recognizes the grace of God’s adoption does not depend on ethnic ties (cf. Romans 9:4-8). In one sense, adoption “belongs” to Paul’s kinsmen in Israel, and at the same time it is not the children of the flesh who are the children of God, but the children of the promise (cf. Romans 9:6-8).
In his letter to believers in Galatia, Paul continues this theme of God’s adoptive grace in the context of the salvation of His people. Paul shows us the contrast between sonship and slavery, with the expectation that believers recognize their divinely granted status of adopted sons of God (cf. Galatians 4:1-7). The person of the Spirit enters the believer and cries out to God as Father. Sonship is the basis of the Spirit’s indwelling and as a result, the Spirit’s indwelling is evidence of sonship (cf. Galatians 4:6). We can see then that a sinner’s justification, adoption, and reception of the Spirit are interconnected, but distinct realities for Paul.
Writing to the church at Ephesus, Paul showed great concern for the purity of the gospel message. He shows how election is according to the predestinating initiative of the triune God (cf. Ephesians 1:3-10). God’s people are those who are adopted by God “through Jesus Christ” (cf. Ephesians 1:5). This connection between sonship and union with Christ points to the image bearing holiness brought about in the life of those who are adopted. This is a good place to remind ourselves that Christ is inherently and eternally the Son of God, while our sonship is derived. Left to ourselves apart from Christ, we would all remain children of God’s wrath, not his favor (cf. Ephesians 2:3).
Closing out Paul’s writings on adoption, Philippians gives us another look at adoption, but this time without the term huiothesia. Paul tells his readers to diligently “work out” their salvation through consistent and gracious obedience (cf. Philippians 2:12-14). The believer’s obedience shows that they are indeed children of God (cf. Philippians 2:14-15). No works, including obedience, can ever be the reason for our salvation but they may be evidence of it. Paul then points his readers to a life of persistent reliance on the word of life, carrying them to the “day of Christ”, and resulting in the validation of Paul’s efforts (cf. Phil 2:15-18).
Adoption in First John
The final NT book we will look at is First John. John calls his readers as “little children” repeatedly throughout this letter (cf. 1 John 2:1,12,28; 3:7,18; 4:4; 5:21). Not only are they John’s “little children”, on a more fundamental level they are God’s children according to by an affirmation of the Father’s love (cf. 1 John 3:1). The status of being a child of God comes with the expectation to balance righteousness with brotherly love by virtue of righteousness and love being inseparable attributes of God’s character revealed in Christ (cf. 1 John 3:10). This obedience is motivated by the love of God and grounded in love for God (cf. 1 John 4:20).
In future articles, we will look at how the doctrine of adoption informs the fields of biblical theology, systematic theology, and how Baptists have historically understood it.
 William Hendriksen, NTC: Exposition of the Gospel According to John – Volume I (Grand Rapids: Baker, 1953), 81-82.
 Herman N. Ridderbos, NICNT: The Epistle to the Galatians (Grand Rapids: Eerdmans, 1953), 158.
 Ronald Y. K. Fung, NICNT: The Epistle to the Galatians (Grand Rapids: Eerdmans, 1988), 187.
 F.F. Bruce, NICNT: The Epistles to the Colossians, to Philemon, and to the Ephesians (Grand Rapids: Eerdmans, 1984), 257.
 F.F. Bruce, The Epistles of John. (Grand Rapids: Eerdmans, 1970), 93.
 Ibid., 116-117.