Heidelberg 33: God’s Eternally And Only Begotten Son And His Adopted Sons (4)

In some quarters of the patristic church and widely in the medieval church the line between God as the Creator and humans as the created became blurred. One of the more important but often overlooked accomplishments of the Reformation was to recover and re-assert this distinction with vigor. Of course the distinction (which, in Recovering the Reformed Confession, I call the categorical distinction) is essential. The Reformed abhorrence to idolatry, whether in the Roman doctrine of transubstantiation or in the use of icons, is grounded in that most biblical datum: In the beginning God. Most pagans, perhaps all of them, want us to think that matter (creation) is eternal. They are willing to allow God (or the gods) to manipulate what already is, what is co-eternal. Only the biblical faith, however, says that there was when the Triune God was and there was nothing else. Only the biblical faith says that God was a se (of himself), that he was utterly self-sufficient  and without need. Sometimes well-meaning Christians give the impression that, before creation, God was lonely or needy. Nothing could be farther from the truth. God is one in three persons: Father, Son, and Holy Spirit. There is an eternal fellowship within the Trinity. It is difficult for us to say a great deal about this because Scripture does not reveal a great deal about this matter but it is suggestive.

Psalm 110 reveals to us something of the eternal fellowship between the Father and the Son. The Apostle Peter makes clear in Acts 2 that Adon of whom the Psalm speaks is not David, whose bones remain in the grave (Acts 2:29). The Adon to whom Yahweh speaks in Ps 110 is the eternally begotten Son of God incarnate, our Lord Jesus Christ. Psalm 2 witnesses to an eternal intra-Trinitarian relationship when Yahweh (v.7) says, ” You are my Son; today I have begotten you.” We see similar images and ways of speaking in the Song of the Suffering Servant in Isaiah 52–53. This eternal fellowship is most clearly revealed, however, in John 17, where our Lord Jesus made his high priestly prayer and, in so doing, gave us a glimpse into the eternal fellowship between the Father and the Son. This prayer reflects an earlier conversation, if you will, between the Father and the Son. Of course, this is homely, ordinary language used to describe what is truly ineffable. Obviously mere humans cannot understand divine, intra-Trinitarian communications! So, our Lord graciously condescends to give us a picture, a way of thinking about the eternal relationship between the Father and his eternally begotten Son. We see this in v. 5 when he says, “And now, Father, glorify me in your own presence with the glory that I had with you before the world existed.” Here he calls to mind the same image present in the prologue (1:1–3): “In the beginning was the Word and the Word was with God and the Word was God….” The expression “with God” suggests two, co-eternal, consubstantial yet distinct persons facing one another. All of this is to say that God was in no need of us. His decree and act to create us was a matter of his good pleasure (beneplacitum).

So, when in our catechism we say:

33. Why is He called God’s “only begotten Son,” since we also are the children of God?

Because Christ alone is the eternal, natural Son of God; but we are children of God by adoption, through grace, for His sake.

We are distinguishing between the being of the Son and our being. The Son was. The Son is. The shall always be. There never was when the Son was not (contra the Arians). The Son must be because God necessarily is. Our theologians tell us rightly that we, on the other hand, are contingent beings, i.e., we (you and I an all creatures) might not be. We exist solely at God’s good pleasure. “And God said, let ‘there be’ and there was.” Until God said “let there be” there was no creature. As creatures, then, our sonship is not a matter of being. Our sonship is a matter of adoption.

Those who believe, who’ve been graciously, sovereignly given new life (regeneration), the gift of faith (Eph 2:8–10), have been adopted according to God’s predestination (Eph 1:5). Paul says that we have received “the Spirit of adoption as sons…” (Rom 8:15). We’re awaiting the consummation of our adoption at the resurrection (Rom 8:23). The Israelites became God’s temporary, adopted national people (Rom 9:4). Now, in the New Covenant, there is no temporary, national adoption but only the adoption that is by grace alone, through faith alone, in Christ alone (Gal 4:5).

Jesus is God’s Son by nature. He cannot be other than God’s Son. He was not adopted, i.e., he did not become God’s Son because God looked at him and decided to choose him to become a son. No, like most other heresies, the 2nd-century Adoptionist heresy confuses the Creator and the creature. Our adoption is by grace alone, through faith alone. It is an enormous privilege. We were more than lonely, hopeless, homeless waifs begging for coins. We were, by nature, in Adam (Rom 5:12–21; Eph 2:1–4) spiritually dead in sins and trespasses. We were lost and did not know it and did not care. We were enemies of God. Nevertheless, of out of his overflowing mercy he did not give to us the justice that we deserved. Out of his grace, God the Son, our Lord Jesus came to obey in our place and to bear the punishment that our sins deserved. “While we were yet sinners, Christ died for us” (Rom 5:8). We were headed for the fire and someone, God the Son incarnate, took the flames for us so that we might be utterly righteous in the sight of God. Yes, in his providence, he still sees our sins but our standing with him has been settled. Now he does not punish us as our sins deserve. We are not in a legal covenant with him but in a gracious covenant. He chastises us yes but only as sons whom he loves (Heb 12:7, 8).

Here’s part 3 of this series.

Here are all the posts on the Heidelberg Catechism.

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  • R. Scott Clark
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    R.Scott Clark is the President of the Heidelberg Reformation Association, the author and editor of, and contributor to several books and the author of many articles. He has taught church history and historical theology since 1997 at Westminster Seminary California. He has also taught at Wheaton College, Reformed Theological Seminary, and Concordia University. He has hosted the Heidelblog since 2007.

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