No longer slaves but sons — and the Spirit teaches us to cry, 'Abba, Father.'
What does it mean that God is your Heavenly Father? In this expository sermon on Galatians 4:1–7, Dr. Toby B. Holt preaches verse by verse on adoption, the crown of the gospel. When the fullness of the time had come, God sent His Son to redeem those under the law, "that we might receive the adoption as sons" (Galatians 4:5, NKJV). Believers are no longer slaves but sons, and God sends the Spirit of His Son into their hearts, crying, "Abba, Father." A Reformed study of how the Father who justifies also adopts, and how His Spirit assures every child He is heard.
0:00 — No Longer Slaves, but Sons. In Christ we are adopted into God's family (Galatians 4).
13:38 — Redeemed From Slavery. The Son was sent to buy us out from under the law (Gal 4:4–5).
20:53 — The Spirit of Adoption. God sends the Spirit of His Son, crying "Abba, Father!" (Gal 4:6).
25:57 — Assurance That You Are His. The Spirit bears witness that we are God's children.
28:27 — A Father Who Hears Your Voice. Like a father who knows his child's cry, God attends to His own.
Paul contrasts a child who is still an heir but lives like a slave under guardians with the freedom of a grown son. So it was with us under the law. "But when the fullness of the time had come, God sent forth His Son, born of a woman, born under the law, to redeem those who were under the law, that we might receive the adoption as sons" (Galatians 4:4-5, NKJV). The passage moves from bondage to sonship through Christ's redeeming work.
Adoption is the gracious act by which God receives the justified into His family, giving them the standing, name, and privileges of sons. The Westminster Confession (chapter 12) calls it being "taken into the number, and enjoy the liberties and privileges of the children of God." It is not earned but bestowed in Christ. John writes, "Behold what manner of love the Father has bestowed on us, that we should be called children of God!" (1 John 3:1, NKJV). Adoption flows from God's free grace.
"Abba" is an Aramaic word for father expressing intimate, trusting nearness, the address of a child who belongs. Paul writes, "And because you are sons, God has sent forth the Spirit of His Son into your hearts, crying out, 'Abba, Father!'" (Galatians 4:6, NKJV). The same cry appears in Romans 8:15. It is not presumption but the Spirit-given confidence of those who know God as their own Father, not a distant judge.
It refers to the appointed moment in God's eternal plan when He sent His Son to accomplish redemption. "But when the fullness of the time had come, God sent forth His Son" (Galatians 4:4, NKJV). The incarnation was not an afterthought or an emergency measure but the precise hour set by God's providence and decree. Reformed theology reads history as governed by God's purpose, and Christ's coming as its long-promised center, anticipated from Genesis 3:15 onward.
Justification is God's legal declaration that the sinner is righteous in Christ; adoption is the relational gift of being made His child. Justification answers the courtroom; adoption brings us into the family. The two are inseparable yet distinct: God does not merely acquit us and leave us strangers, He names us sons and heirs. "Therefore you are no longer a slave but a son, and if a son, then an heir of God through Christ" (Galatians 4:7, NKJV).
The Westminster Confession of Faith devotes chapter 12 entirely to adoption. It teaches that all who are justified are received into God's family, have His name put on them, receive the Spirit of adoption, have access to the throne of grace with boldness, are protected and provided for as by a father, and are never cast off but sealed to the day of redemption. This directly reflects Galatians 4:5-7, where sonship, the Spirit, and inheritance are joined.
An heir possesses a future inheritance by right of family. Paul concludes, "and if a son, then an heir of God through Christ" (Galatians 4:7, NKJV). The believer's inheritance is God Himself and all the blessings of His kingdom, secured not by personal merit but by union with Christ, the true Son. Because the Son will never be disinherited, neither will those who are in Him. The phrase "through Christ" guards the gospel: every privilege of sonship is mediated.
The Spirit assures believers by witnessing within them that they belong to God. In sending "the Spirit of His Son into your hearts, crying out, 'Abba, Father!'" (Galatians 4:6, NKJV), God grounds assurance not in feelings alone but in His own work. Romans 8:16 says the Spirit "bears witness with our spirit that we are children of God." Reformed teaching holds that this assurance comforts the believer especially in the fight against sin, since the Father will not cast out His own.
Before Christ, people stood under the law as minors and slaves, bound and fearful. Through redemption that status is decisively changed. "Therefore you are no longer a slave but a son" (Galatians 4:7, NKJV). The believer relates to God not as a hired servant earning wages but as a beloved child who already belongs. This does not abolish obedience; it transforms its motive from fear of punishment to the love and freedom of family.
Calling God "Father" names the new relationship the gospel creates: adopted children, not condemned outsiders. It assures us that the God who governs all things attends to His own with fatherly care, hearing their cry. Yet Scripture reserves this name for those who are in Christ, for "as many as received Him, to them He gave the right to become children of God" (John 1:12, NKJV). The Fatherhood of God is a gospel gift, not a universal given.
1. Adoption as Sons Through Christ
Adoption is the gracious act by which God receives the justified into His own family. It is the goal stated in the passage: God sent His Son "to redeem those who were under the law, that we might receive the adoption as sons" (Galatians 4:5, NKJV). Sonship is not native to us; it is bestowed through Christ, the eternal Son. The Westminster Confession (chapter 12) treats adoption as a distinct grace, granting the name, liberties, and privileges of God's children to all who believe.
2. Redemption From Slavery Under the Law
Before adoption comes redemption. Paul pictures humanity as minors and slaves, in bondage under the elements of the world, until God acted at the appointed hour. "God sent forth His Son, born of a woman, born under the law, to redeem those who were under the law" (Galatians 4:4-5, NKJV). Christ entered our condition and bore the law's curse in our place (Galatians 3:13). Sonship is therefore purchased, not presumed, grounded entirely in the finished work of Christ the Mediator.
3. The Spirit of Adoption and the Believer's Assurance
God does not leave His children uncertain. He sends the Spirit to confirm their place in the family and to teach them to call Him Father. The Spirit cries within the believer, "Abba, Father," producing not slavish fear but the confidence of a child who is heard. This inward witness, joined to the truth of God's Word, anchors assurance. Because the Father loves His adopted children in the beloved Son, He will never cast them out but keeps them as His own.
The Scripture Text: Galatians 4:4-7 (NKJV)
"But when the fullness of the time had come, God sent forth His Son, born of a woman, born under the law, to redeem those who were under the law, that we might receive the adoption as sons. And because you are sons, God has sent forth the Spirit of His Son into your hearts, crying out, 'Abba, Father!' Therefore you are no longer a slave but a son, and if a son, then an heir of God through Christ."
Continue studying: explore the full Book of Galatians sermon series, or browse the complete Reformed Sermon Archive.
About The Speaker: Dr. Toby Holt serves as the third President of New Geneva Theological Seminary (Colorado Springs, CO), founded 1993. An expository preacher with over 1.9 million sermon downloads on SermonAudio.com, Dr. Holt brings over 17 years of pastoral experience to his verse-by-verse Bible teaching. New Geneva offers fully online Reformed theological education — M.Div., Th.M., D.Min., and other degrees.
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