At the heart of the Gospel lies the doctrine of union with Christ.
In many ways, union with Christ explains how we are saved, the implications of our salvation in the daily life of faith, and the end-goal of salvation. We are saved through union with Christ. We live our life of faith by union with Christ. And we are saved for ultimate, eschatological union with Christ.
In his book Deeper: Real Change for Real Sinners, Dane Ortlund points out that the topic of union with Christ comes up on average every other page in the New Testament. This is clearly a central theme of New Testament scripture. We may not immediately recognize every reference to union with Christ because those exact words aren’t used frequently. But phrases like “in Him/Christ”, “through Him/Christ”, and so on are everywhere.
This is the first in a series of articles dedicated to the doctrine of union with Christ. This series will examine topics like sanctification, eschatology, adoption, and fellowship with God through the lens of union with Christ. In this first installment, we’ll examine the covenantal framework that serves as a basis and foundation for the doctrine of union with Christ and the Gospel itself. The main passage we will look at is Romans 5:12-21.
In Adam’s Fall, We Sinned All
Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned— for sin indeed was in the world before the law was given, but sin is not counted where there is no law. Yet death reigned from Adam to Moses, even over those whose sinning was not like the transgression of Adam, who was a type of the one who was to come.
Romans 5:12-14, ESV
Our understanding of union with Christ must go all the way back to the Garden of Eden in Genesis for its full context.
God created the world and at its pinnacle He placed Man and Woman. We do not have space for an in-depth study of Man’s original commission here so a summary must suffice: God created Man (Adam), placed him in the Garden, and gave him a commission to fill the earth and subdue it. He also charges Adam to “keep and work” the Garden, implying protection and cultivation. While the Woman is given to Adam as an equal, she is a helper in this commission which Samuel Renihan points out is given to Adam before the arrival of the Woman¹.
Thus, God makes a covenant with Adam, promising (through implication) that he will receive eternal life if he obeys but promising death if he disobeys the commandment to refrain from eating the Tree of the Knowledge of Good and Evil.
This covenant is made with Adam, who represents all his offspring. In covenanting with Adam, God covenants with all his descendants (i.e. all humanity). As Renihan puts it, “All humanity, our Lord excepted by virgin birth, were thus represented in Adam.”²
Adam is what theologians call a “federal head”. Just as we are represented in the federal congress by a representative, so also a federal head refers to one man who represents a wide group who are intimately related to him. God’s covenants are often directed towards one federal head: Adam, Abraham, David, etc. Their offspring, those “united to them”, are included in the covenant promises and stipulations.
As federal head of the human race, Adam’s actions were the actions of all of humanity. That is why Paul says in Romans 5:18 that “one trespass led to condemnation for all men”. We all know the tragic story: Adam and the Woman did not abide by God’s covenant commandments and they sinned. They were cast out of the Garden.
The New England Primer, a colonial schoolbook, taught children that “in Adam’s fall, we sinned all”. This is not just a figure of speech. The Scripture is clear: Adam’s sin and guilt is our sin and guilt. We are certainly responsible before God for our own individual sin but we are also condemned for Adam’s sin. In fact, we are born guilty. We are not born morally neutral. We are not born with a clean slate that we all muddy with our sin. We are born with what is called “original sin”. This is sin and guilt inherited from our father, ultimately our forefather Adam.
This is why the virgin birth is an essential doctrine of the Christian faith. If Jesus Christ was conceived by the union of a human father and mother he would not have been sinless. He would have been united to Adam as His covenantal federal head and would have thus inherited Adam’s sin and guilt. The cross would lose its power. The Gospel itself would fall apart.
This may seem deeply unfair to us. We want God to hold us responsible for our own actions, not the actions of a man who lived thousands of years ago that we have no control over. We consider it unfair to be condemned for Adam’s sin. We never asked for him to represent us after all! We didn’t “vote” for him!
But we misunderstand the covenantal foundation of the Bible and the Gospel. This is the way God has, in His wisdom, chosen to structure the world. And it’s a good thing for us.
A New Adam
But the free gift is not like the trespass. For if many died through one man’s trespass, much more have the grace of God and the free gift by the grace of that one man Jesus Christ abounded for many. And the free gift is not like the result of that one man’s sin. For the judgment following one trespass brought condemnation, but the free gift following many trespasses brought justification. For if, because of one man’s trespass, death reigned through that one man, much more will those who receive the abundance of grace and the free gift of righteousness reign in life through the one man Jesus Christ.
Romans 5:15-17, ESV
The good news is that Jesus Christ came to stand in our place and stand as the New Adam for a New Humanity. We read in Romans that Adam’s sin (one trespass which brought condemnation to all) is contrasted with Christ’s obedience (one act of righteousness which brought grace to many).
We are saved by grace through faith and this is a free gift (Eph. 2:8-9). This is afforded to us by the covenantal relation of a new federal head, Jesus Christ. When faced with temptation to follow His own will in the garden, Christ said “not my will but your’s be done” (Luke 22:42).
Jesus’ surrender to His Father’s will and His willing ascent to the cross was the ultimate act of obedience which brought grace and justification for humans through the ages. This, I believe, is what Paul is referring to when he writes about “one man’s obedience” (Rom. 5:19). But Jesus’ entire life was one of obedience. As I’ve noted elsewhere, the temptation of Christ in Luke 4 was a “new Adam” moment of decision. (This is supported exegetically by the context of Luke 3:38.)
Two Human Races
Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. For as by the one man’s disobedience the many were made sinners, so by the one man’s obedience the many will be made righteous.
Romans 5:18-19, ESV
When we are united to Christ by faith we are transferred to representation by Christ Jesus’ obedience and no longer under the condemnation of Adam’s disobedience.
Imagine there are two columns in a book. At the heading of one column is the name “Adam” and the heading of the other is “Jesus Christ”. Every name of every human being that has ever lived and ever will live is written under Adam’s column. When we are united to Christ by faith and the Holy Spirit’s regeneration (that is, born “again” into a new human race, see John 3:5) our name is transferred to Christ’s column. Now He represents us.
We are condemned by our association and representation by Adam. But “in Christ” we are justified and have eternal life. This is the heart of the New Covenant, Christ is the federal head of the New Covenant, just as Adam was the federal head of God’s covenant with him (i.e. the Adamic covenant or covenant of works).
Samuel Renihan writes: “The Covenant of Redemption is the foundation of the New Covenant. The covenant of redemption was a covenant of works from the Father to the Son. The Son had a mission, a work to complete, with a reward suspended on condition of His obedience. Jesus willingly and perfectly fulfilled the Covenant of Works. He Himself said that it is finished.”³
We don’t have space to go into detail about the “covenant of redemption” but Renihan lays it out well in The Mystery of Christ: His Covenant and His Kingdom. Essentially, to summarize, the covenant of redemption is the name given to the covenant made between God the Father and God the Son before time began. It includes the will of the Father to redeem a people yet unborn for the Son. Upon the Son’s obedience, He would inherit the glory of His Kingdom. Renihan notes, “The Scriptures portray, in the mode of covenant, an intra-trinitarian dialogue between the Father, the Son, and the Holy Spirit concerning the redemption of an elect people.”⁴
So the Gospel blessings we receive are through received through our union with Christ. Jesus Christ has won an inheritance and we are counted as fellow heirs with Him through our union with Him as our covenantal representative.
Paul summarizes this glorious truth at the conclusion of chapter 5 of Romans:
Now the law came in to increase the trespass, but where sin increased, grace abounded all the more, so that, as sin reigned in death, grace also might reign through righteousness leading to eternal life through Jesus Christ our Lord.
Romans 5:20-21
In Adam we have trespass, sin, guilt, condemnation and at the end of it all: death. In Christ we received Jesus’ imputed obedience and righteousness. This leads to grace and eternal life.
This is the structure of union with Christ. To say that we are “united with Christ” is to say, using the language of the New Testament and Pauline theology, that we are covenantally represented by Jesus Christ, no longer Adam. We are still humans but we belong to a redeemed and “born again” human race. Our Adam is Jesus. In future articles, we will examine what implications this has for us, starting with implications for our sanctification.
¹ Samuel Renihan, The Mystery of Christ: His Covenant and His Kingdom, (Cape Coral: Founders Press, 2020), 62.
² Ibid, 62-63.
³ Ibid, 170.
⁴ Ibid, 154.