I recently enjoyed reading J.I. Packer’s modern classic Knowing God, and I have to say that the chapter on adoption (Chapter 19: “Sons of God”) is worth the price of the entire book. Packer writes that being called a son of God is the richest and highest answer to the question “What is a Christian?” This was also one of the longest chapters of the book, so it’s a bit difficult for me to distill down. But because Packer views adoption with such high regard, he writes that “if [the thoughts of having God as one’s Father] are not the thoughts that prompt and control his worship and prayers and his whole outlook on life, it means that he does not understand Christianity very well at all.” In reading the chapter, I realized how little I mediate on the fact that I have been adopted as God’s son and what a glorious truth that is.
Packer writes that adoption is the highest privilege that the gospel offers – even higher than justification. Justification is indeed a wonderful truth, but because of its forensic nature – “conceived in terms of law” – it does not automatically assume an intimate, deep relationship with God, the Holy Judge. In fact, as Packer points out, justification by itself may connote that the justified has an obligation to be the servant of the justifier. But Jesus calls us friends (John 15:15), and elsewhere we are called sons of God (John 1:14, etc.). Adoption is a familial idea, in which God, of His own free grace, receives us “into the number, and [we] have a right to all the privileges of the sons of God” (WSC 34). What manner of love this is! (1 John 3:1)
Justification and adoption are so intertwined that they can’t be separated. “We do not fully feel the wonder of the passage from death to life which takes place in the new birth till we see it as a transition, not simply out of condemnation into acceptance, but out of bondage and destitution into the safety, certainty, and enjoyment of the family of God. This is the view of the great change which Paul sets out in Galatians 4:1-7.”
Packer goes on to comment that when immaturity, depression, and randomness plague a Christian, it could be from them not dwelling on the “health-giving” abiding security of being a son of God and what that means. I know this is true for me – I’ve found that meditating on adoption helps me combat sin and temptation in my life and is also encouraging, strengthening, and refreshing. “It is not as we strain after feelings and experiences, of whatever sort, but as we seek God Himself, looking to Him as our Father, prizing His fellowship, and finding in ourselves an increasing concern to know and please Him, that the reality of the Spirit’s ministry becomes visible in our lives.”
Further, adoption and justification also complement one another related to the law. While justification by grace through faith frees us from the need to keep the law as a means to eternal life, adoption “lays on one the abiding obligation to keep the law, as the means of pleasing one’s Father.” In other words, law keeping for the believer is not obsolete or merely something that was done in the Old Testament, but is in fact an aspect of the familial likeness of being a son of God.
As children of God, the law has authority over us as a rule for our lives because God has commanded us to follow it as His children. No one, including God’s children, can keep the law perfectly, but because of our intimate relationship with Him as our Father, when we sin, we run to our Father and confess our sins; and our Father is faithful and just to forgive us our sins on the basis of that familial relationship. What a great thing adoption is.