I wrote this study for Paul’s Shorter Epistles at Bob Jones University in the fall of 2001 and lightly revised it in 2009.
Introduction: There is probably not a more all-encompassing theme of the gospel as it is revealed in the NT than the theme of the believer’s union with Christ. The gospel is essentially the gospel of Christ. There is no gospel apart from Him. Paul, in the opening of his epistle to the Ephesians, breaks into praise of God saying, “Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ” (1:3). The totality of spiritual blessings that the believer has and experiences is inseparably linked to Christ. Christ, in His perfect and substitutionary active obedience by which He earned righteousness for His people and passive obedience by which He removed the sin of His people, is the sole ground or basis for every blessing of a spiritual nature. This “in Christ” theology pervades Paul’s writings. In 1 Corinthians 1:30 Paul emphasizes that the summation of the Christian life and experience is bound up in Christ by saying, “But by His doing you are in Christ Jesus, who became to us wisdom from God, and righteousness and sanctification, and redemption.” Again, Paul makes the sweeping statement in 2 Corinthians 1: 20, “For as many as are the promises of God, in Him they are yes; therefore also through Him is our Amen to the glory of God through us.” Christ is the gospel. He is our salvation. Therefore Paul could also say, “In Him you have been made complete” (Colossians 2:10). Every aspect of the believer’s salvation and experience is intrinsically connected to Christ, and therefore having Christ is having it all.
Union with Christ may be illustrated this way. A necklace with various beads or shells represents the gospel. Each individual piece of the necklace stands for a different aspect of the gospel. There is the bead of foreknowledge, of predestination, of election, of effectual calling, of regeneration, of conversion, of adoption, of justification, of sanctification, of glorification, and so forth. But these beads are separate and individual apart from the string that holds them all together and gives them unity. Without the string there is no necklace, only individual beads. Christ and our union with Him is the string that unites all of the elements of the gospel. Take out Christ and our union with Him, and you have taken out the essence of the gospel. Union with Christ is the heart of the gospel. John Murray said it well in his book Redemption—Accomplished and Applied, “[Union with Christ] embraces the wide span of salvation from its ultimate source in the eternal election of God to its final fruition in the glorification of the elect. It is not simply a phase of the application of redemption; it underlies every aspect of redemption both in its accomplishment and in its application” (165, Quoted from Reymond’s Systematic).
The NT illustrates this doctrine in many different ways. There is the illustration of a building and its chief stone (Eph. 2:19–22; 1 Pet. 2:4–5), a vine and its branches (John 15:1–8), a body and its head (Eph. 4:15–16), a marriage relationship between wife and husband (Rom. 7:1–4; Eph. 5:22–23; Rev. 19:7; 21:2–9), a covenantal relationship between the human race and Adam (Rom. 5:12–19; 1 Cor. 15:22, 48–49), and even the relationship of the members of the Godhead (John 14:23; 17:21–23). Here is a series of messages to unfold all the rich implications of these inspired illustrations. But regardless of the illustration used, the point is the same—the believer’s life consists of Christ.
This theme of union with Christ is most fully developed and expounded by the apostle Paul. It pervades his epistles, giving unity to all of the elements of the gospel, uniting Christian doctrine and duty. This central element of the gospel was first revealed to Paul at his conversion experience on the road to Damascus. Acts 9:1–5 records this: “Now Saul [was] still breathing threats and murder against the disciples of the Lord…. [And] as he was traveling, it happened that he was approaching Damascus, and suddenly a light from heaven flashed around him; and he fell to the ground and heard a voice saying to him, ‘Saul, Saul, why are you persecuting Me?’ And he said, ‘Who are You, Lord?’ And He said, ‘I am Jesus whom you are persecuting.’” Paul, in his very first encounter with Christ, learned the fundamental point that Christ and His people are united together in a real and living union. Thus, for Paul to oppose the Church was to oppose the Head of the Church.
What is union with Christ? What does Paul mean by “in Christ”? This concept can be somewhat vague and ethereal. So a brief definition may help to give some substance to what it is that union with Christ really means. The Larger Catechism defines our union with Christ as follows: “The union which the elect have with Christ is the work of God’s grace whereby they are spiritually and mystically, yet really and inseparably, joined to Christ as their head and husband” (Question 66). The essence of this doctrine is being connected with Christ and sharing with Him in all of the fruits of His person and work.
Illustration: Although this illustration is lacking in many regards, it may be helpful in communicating one aspect of the believer’s union with Christ. This year I have a little brother here at the University as a freshman. Many people have met him and referred to him as “Phil’s brother.” Because of his relationship with me, people have, to an extent, dealt with him in terms of me. Those who are my close friends automatically accept him and regard him as a friend. This is one of the privileges of being in a familial relationship with someone. People often treat you in terms of who they know you are related to or associated with. This is something of what it means to be in union with Christ, especially as it regards how the Father deals with us. He always deals with us in terms of His Son.
It is impossible to be exhaustive as we deal with Paul’s epistles here, especially in one sermon. To do so could easily fill a year’s worth of sermons. So we will be suggestive of some of the major themes and emphases that Paul relates with our union with Christ.
I. In Him by Plan: Union with Christ in Eternity
Paul, in the opening of the epistle to the Ephesians, as he expounds upon our union with Christ, begins in eternity past with our election. As far back as Scripture goes in discussing the believer’s salvation is his union with Christ. This union was as good as reality in the mind and purpose of God before the creation of the world. And as Paul makes clear in Ephesians 1:4–5, you cannot talk about election without talking about election in Christ. As was stated earlier, union with Christ was not an afterthought tacked on in history. It is the essence of the gospel from all eternity.
One point worth noting here is that while our union with Christ is planned and certain and in a sense reality in God’s eternal plan, it does not become the experience of the believer until conversion. He remains a child of wrath (Eph. 2:3) and separate from Christ (Eph. 2:12) until he repents and turns to Christ is faith.
A. Union with Christ in Love
In Romans 8, Paul is dealing with the assurance that believers can have in the face of trials and suffering. He points to God’s eternal unfrustratable plan to give confidence to believers to hope in God. In the last section (31–39) Paul mentions God’s love for His people either explicitly or implicitly a number of times. And in verses 38–39 we find these words concerning our union with Christ: “For I am convinced that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers, nor height, nor depth, nor any other created thing, will be able to separate us from the love of God, which is in Christ Jesus our Lord.”
The essence of the biblical teaching on God’s love is that God loves His people with the love with which He loves the Son. It is our union with the Son that makes us equal objects of His love. What a love we experience because we are “in Christ”!
B. Union with Christ in Predestination
The word predestinate in the Greek is προορίζω—a word which literally means “to determine (the boundaries of) before.” Paul draws the connection between predestination and union with Christ by saying, “In love He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will” (Ephesians 1:5). Our predestination is through Christ. And as Romans 8:29 makes clear, not only was our predestination through Christ, it was also unto conformity to Christ as its goal and purpose. “For those whom He foreknew, He also predestined to become conformed to the image of His Son, so that He would be the firstborn among many brethren.” Everything about our predestination is intrinsically connected to Christ.
Paul states clearly as well that God’s choice of us was “in Christ” in saying, “He chose us in Him before the foundation of the world, that we would be holy and blameless before Him” (Ephesians 1:4). The freeness of God’s election planned our union with Christ in eternity. Let us never get over the wonder of this glorious truth!
II. In Him in Position: Union with Christ in Conversion
A. Union with Christ in Justification
One of the clearest texts dealing with the believer’s union with Christ in justification is found in 2 Corinthians 5:21, which says, “He made Him who knew no sin to be sin on our behalf, so that we might become the righteousness of God in Him.” Because Christ is righteous those who are united to Him share in His righteousness. At the heart of the gospel, and thus at the heart of our union with Christ, are substitution and imputation—God dealing with Christ in terms of His people and dealing with His people in terms of Christ. Union with Christ concerns the double exchange that took place between Christ and believers. There is the imputation of all of the demerits of all who believe in Christ to Him and the imputation of all of the merits of Christ to them. By His life He earned the necessary righteousness through obedience to the law for all those in union with Him, which God credits to their account by faith. And by His death He paid the necessary penalty for the broken law for all those in union with Him. This is the heart of the gospel.
Because the problem of man is twofold—negatively, the penalty due for the broken law, and positively, the reward given for the fulfilled law—the provision of Christ is twofold as well, dealing with both man’s need for forgiveness and his need for righteousness.
1. Union with Christ in His passive obedience
A common theme throughout the NT is the union of the believer in the death of Christ (Rom. 6:2, 8; Col. 2:20; Col. 3:3). Because of the believers union with Christ, God considers all of the work of Christ in paying the penalty for sin as being the believer’s own payment.
Illustration: This aspect of union with Christ may be illustrated this way. Suppose you have a large debt, a debt which you are unable to pay off. The harder you try, the deeper you get. The payments are too much to keep up with. But someone offers to pay your debt in full, removing any responsibility on your part to pay anything. This is the essence of being united to the cross work of Christ.
2. Union with Christ in His active obedience
An element of our salvation that is often neglected today it the positive crediting of righteousness to the believer’s account. Forgiveness of sins is only half of being in union with Christ and His work in justification. Notice the text again in 2 Corinthians 5:21, “He made Him who knew no sin to be sin on our behalf, so that we might become the righteousness of God in Him.” The reason Christ became sin is so that we might become righteousness.
Illustration: To continue the illustration from above—this individual pays your debt in full. But this would still leave you in poverty. You have no job and no money. Your possessions have all been confiscated. But this man does not leave you in your poverty to fend for yourself. He also decides to give you access his bank account, for he is a multi-billionaire. This is what Christ has done for His people. He has granted them forgiveness by paying for their sin, and He has clothed them in His righteousness by living a perfect life of obedience to God.
Application: Do you claim your own righteousness before God? Do you think God accepts you more or less depending upon your performance? Why do you come to church? Why do you read your Bible and pray? Why do you share your faith? You must, in doing things for God, never be seeking to gain a greater acceptance with Him. The totality of your favor with God is the favor that Christ has with God, which has become yours by faith. God is pleased when we rest in the merits of His Son.
B. Union with Christ in Adoption
Another element of the gospel connected to our union with Christ is our new place in the family of God. Paul again stresses that our adoption finds its ground in that “He predestined us to adoption as sons through Jesus Christ to Himself” (Eph. 1:5). The believer’s new position as a son of God is as a result of the work of the Son of God. In Romans 8:17, believers are referred to as “heirs of God and fellow heirs with Christ.” All of the rich familial blessings of the family of God belong to us as children of the Father and brothers of the Son.
Illustration: As a child, I remember thinking on a couple of occasion that I would like to be in someone else’s family. My parents we too strict or had done something to upset me. And I thought, if only some other people were my parents, then I would not have to put up with this. I was childish and selfish then. But in the same way, there is no more enviable position in the entire world to be in than the family of God.
III. In Him in Practice: Union with Christ in Sanctification
The practicality of union with Christ is overwhelming in Paul’s epistles. Probably the most thorough exposition of the implications of union with Christ to daily life and sanctification is found in Romans 6. Paul sees the believer’s union with Christ as the ground for righteous and holy living. He continually points to this reality as the basis for moving on in the Christian life in obedience. In Colossians 3 as well, Paul discusses the believer’s union with Christ in His death, burial, and resurrection, and then he immediately follows with οὖν, commanding believers to put to death the sinful behavior of the old man in verses 5–9 and to behave righteously in verses 12 and following. Paul is essentially saying, “Live out the reality of what you really are in standing before God.” The essence of sanctification, bringing our practice in line with our justification, is a recognition of, belief in, and behavior according to our union with Christ.
A. Union with Christ in His death and burial
The believer, being united to Christ, has died to sin. When Christ was crucified, the old man was crucified with Him. In Romans 6:6–7 Paul says, “Knowing this, that our old self was crucified with Him, in order that our body of sin might be done away with, so that we would no longer be slaves to sin; for he who has died is freed from sin.” Prior to conversion, the sinner is a slave. He must sin; that is his only option. But when he experiences union with Christ, the old man dies and the believer is freed from his old master. Sin no longer has dominion over him.
Illustration: Imagine that you are in prison. You are locked up and in chains, unable to do anything but sit there. But one day, you are set free. Your chains are removed, you are given new clothes, and you are brought into a beautiful new house. Your bondage is over. You are free. But for some reason you sit in the bedroom of your new home as if he were still imprisoned and in chains. Finally, the man who had set you free comes to visit and see how you are doing, only to find you sitting in your room. The man looks at you and asks you what you are doing. “You are free now. You can begin a new life. Your chains have been removed.” This is Paul’s message to so many Christians struggling with sin.
Application: This is heart of Paul’s message to you. You do not have to sin anymore. Prior to conversion you were bound in the chains of sin and had not choice but to sin. Now, having been united to Christ in His death, burial, and resurrection, you do not have to sin. Consider yourself in experience what you are in standing before God. Live in light of your union with Christ.
B. Union with Christ in His resurrection and life
But as in justification God does not grant us forgiveness apart from righteousness, in this aspect of our union with Christ, God does not grant us release from the slave master of sin without also giving us a new Slave Master. Paul says now that the believer is a slave of righteousness: “But thanks be to God that though you were slaves of sin, you became obedient from the heart to that form of teaching to which you were committed, and having been freed from sin, you became slaves of righteousness” (Rom. 6:17–18).
Illustration: The imagery here is that of a slave. Picture yourself as having been a slave to a cruel and wicked man, only latter to be released by a kind and loving man. He pays your current owner to set you free and makes you his very own. But your new master, although you have requirements that you must keep, is a kind a loving master who takes care of your every need and allows you to share in the great abundance of His wealth. This is the essence of being united to Christ in His resurrection, so that now you can walk in newness of life, living as servants to a new master.
Application: Who is the master of your life? Have you recognized that you are no longer a slave to sin? Paul says the key to righteous living is recognizing your union with Christ in His death and resurrection. Why do you still continue in your anger? Why do you still give in to your lusts? Paul says that you must recognize your union with Christ, believe your union with Christ, and behave in light of your union with Christ.
C. Union with Christ in His ascension and session
Our union with Christ is so real and inseparable that Paul could even go to the extreme and say, “[He] made us alive together with Christ (by grace you have been saved), and raised us up with Him, and seated us with Him in the heavenly places in Christ Jesus” (Eph. 2:5–6). Even though now in experience we are here on the earth in the flesh, our union with Christ is so real that Paul could refer to us as already seated with Christ in heaven. Although not physically connected, the believer’s spiritual union with Christ is no less a real union.
IV. In Him in Perfection: Union with Christ in Glorification
The believers union with Christ finds its ultimate consummation in glorification where the believer for the first time becomes one with Christ, both in position and experience. During the Christian life, there is this continual tension between position and experience. In glorification, the Christian’s experience of his union with Christ becomes equivalent to his position. He comes to experience, in the fullest sense, what it means to be “in Christ.” In Romans 8:16–17 Paul says, “The Spirit Himself testifies with our spirit that we are children of God, and if children, heirs also, heirs of God and fellow heirs with Christ, if indeed we suffer with Him so that we may also be glorified with Him.” The glory that Christ experienced when God exalted Him to the throne on high will be experience by every believer in Christ. While this union can be very mystical and abstract, it is yet very real and vital. What a wonderful experience we have to look forward to in the full realization of this wonderful union with Christ!
Conclusion: From eternity past, to the cross, to conversion, to Christian experience, to glorification, and into all eternity, the believers union with Christ gives meaning to Christian salvation. This union with Christ is the source from which come “all spiritual blessings.” Christ is the fountainhead of all of God’s gracious working with His people. He is the sum and substance of the gospel. The gospel is as simple as having the Son. “He who has the Son has the life; he who does not have the Son of God does not have the life” (1 John 5:12). To be connected to Christ is to have the abundant life. And while the gospel is simply to be connected to Christ, the greater one’s understanding of Christ and His work—and thus of one’s own union with Christ—the greater will be the enjoyment of Christ and His gospel, and the greater the success of one’s Christian experience. Let us realize that the Christian is never to get over the gospel. From eternal election, to his standing before God, to every day life and experience, the believer’s life is Christ and His gospel; and therefore his chief pursuit must be to know, obey, enjoy, and proclaim the gospel of Christ. Have you gotten beyond the gospel? Come back to the gospel for your contentment, for we are indeed “complete in Him.” And learn to live in light of your union with Christ.
Barrett, Michael P. V. Complete in Him: A Guide to Understanding and Enjoying the Gospel. Greenville, SC: Ambassador–Emerald, 2000.
Calvin, John. Institutes of the Christian Religion. Grand Rapids: Eerdmans, 1997.
Gaebelein, Frank E. The Expositor’s Bible Commentary: Volume 11 (Ephesians – Philemon). Grand Rapids, MI: Zondervan, 1978.
Murray, John. Redemption Accomplished and Applied. Grand Rapids: Eerdmans, 1984.
Reymond, Robert L. A New Systematic Theology of the Christian Faith. Nashville: Thomas Nelson, 1998.
Westminster Confession of Faith. Glasgow: Free Presbyterian, 1995.