INTRODUCTION: God’s eternal plan to save His people is that they should have salvation by union with the Only Begotten Son of God (2 Tim 1:9). By radical identification with Christ, our sins became His and His righteousness became ours (see 2 Cor 5:21). (Note that Reformed theologians observe that there never was a time in eternity past when God contemplated the elect apart from their being “in Christ.”)
Christ’s righteousness belongs to believers by virtue of union with Christ (Rom 5:19; 1 Cor 1:30; Phil 3:9; 1 Pet 2:24).
So fully is the believer identified with Christ that what Christ earned for us is rightfully ours as if we had earned it ourselves (1 Pet 1:3-5; Col 3:3-4). His dying and raising is applied to us personally – it is the basis for newness of life in Him.
Notice how many “in Christ” passages there are in N.T. (“in Christ” is used 216 times by the Apostle Paul). All the believer’s blessings are in Christ as a source.
I. The definition of Union with Christ
“Union with Christ is a phrase used to summarize several different relationships between believers and Christ, through which Christians receive every benefit of salvation. These relationships include the fact that we are in Christ, Christ is in us, we are like Christ, and we are with Christs” (Wayne Grudem, Systematic Theology, p. 840).
II. The Biblical Illustrations of Union with Christ
How is the believer united to Christ? How have Christians died in Him? OBJECTION: These descriptions of the Christian’s union with Christ may sound like theological word games, but they speak of a reality that is central to all Christian doctrine. ANSWER: The Bible provides much for our faith and inquiry by way of illustrations of our mystical union with Christ. (It is a “mystical union” because there is nothing exactly like it on earth.) Note the following biblical illustrations of union with Christ:
A. The relationship between stones in a building (believers) and the building’s chief cornerstone (Christ) (Eph 2:19-22; 1 Pet 2:4-50.
B. The relationship between branches of a vine (believers) and the main vine itself (Christ) (John 15:1-80).
C. The relationship between members of a body (believers) and the body’s head (Christ) (Eph 4:15, 16). The Headship of Christ is His Lordship over believers. Our relationship to Christ as Head is a living, growing, union. It is an organic union in which Christ Himself takes up residence within the individual. It’s impossible that man can produce this union – it is not established by any religious act, including membership in a biblical church. (EXAMPLE: The pituitary gland in the head is the master gland that controls the growth of the whole body. Christ controls our growth.) (See also Eph 1:22, 23; Col 1:18; 1 Cor 12:12-27).
D. The relationship between a wife (believers) and a husband (Christ) (Eph 5:22-23; Rom 7:4).Note how marriage changes so many aspects of one’s life: intimacy, legality, name change, fruitfulness. The husband and wife are bound together legally. All their legal affairs are conducted in oneness. This throws light on our union with Christ as the basis of salvation. Through union with Him as our faithful Bridegroom and husband, He is able to pay the penalty which we have incurred because of sin. There are numerous psychological and social changes as well. The wife regards other men very differently now. Old relationships change. There is a shared status with one’s husband and a sharing in his station in life. Ultimately, the believer will “gain the glory of our Lord Jesus Christ” (2 Thess 2:14).
E. The relationship of solidarity between the race (and Adam) which descended from Adam by ordinary generation and Adam himself (Rom 5:12-19; 1 Cor 15:22; 48-49).
F. The relationship between the Persons of the Godhead (John 14:23; 17:21-23).
APPLICATION: The believer’s union with Christ is as real as if an umbilical cord were stretched from you to Christ in heaven. He is the entire source of your spiritual life. He is your life, your very viability. There would be no spiritual life without union with Him. (An additional example is provided by the astronaut who journeys out from the mother ship by way of an “umbilical cord.”) Union is NOT the loss of one’s personality by merging into Christ. That would be like a raindrop falling into the Pacific Ocean; it is then no longer a rain drop at all, but a part of the ocean.
III. The Gracious Cause of Union with Christ
A. The Father’s eternal counsels of redemption planned the salvation of sinners (Eph 1:4). The Son was sent to seek and to save that which was lost (Lu 19:10). “Christ did not come to represent a disjointed conglomerate of people – He came to die for those who would be saved by union with Him” (Louis Berkhof, Systematic Theology, p. 448).
B. The sovereign grace of God alone puts us in union with Christ (1 Cor 1:30-31; James 1:18). The Father poured out His infinite grace IN the One He loves – that means that all of God’s grace comes to us in Christ (Eph 1:6; 1 Cor 1:4). This was a planned union by God’s own decision. It was not conditioned upon what God saw that you would do (see 2 Tim 1:9; Eph 1:11, 13; Gal 2:20; faith is the instrument 3:26). Even saving faith is traceable to God’s grace (see Phil 1:29; Eph 2:8, 9).
C. We are God’s workmanship (Eph 2:10; 2 Cor 5:17). The believer is “complete” in Christ (Col 2:10). Christ is our life (Col 3:3, 4).
D. The believer’s union with Christ was planned in eternity (Eph 1:4). It was objectively actualizedin Christ’s death and resurrection (Rom 6:5). It was subjectively realized in the baptizing ministry of the Holy Spirit (1 Cor 12:13). “The flesh of Christ is like a rich and inexhaustible fountain that pours into us the life springing forth from the Godhead into itself” (Calvin’s Institutes, IV. 17.9.). Calvin’s point is we cannot share in Christ’s saving benefits without possessing Him.
E. The Holy Spirit unites the believer to Christ (1 Cor 12:13). Union is coincident with regeneration – it takes place at the moment of the new birth (Gal 3:27). The Holy Spirit regenerates the sinner (Titus 3:5-7). There can be no new life UNTIL the bondage of sin and self is broken (Rom 6:2-7; 2 Cor 5:14-15, 17). Christ’s death and resurrection is the basis for imparting new life to the believer. His death was the judgment of our old life (Rom 6:6). Who and what we were before we met Christ was judged at the cross – it is slated for demolition, not improvement. (Note that false forms of “Christianity” major in attempts to patch up and fix up the “old man” – Rom 6:6 teaches us that victory over sin’s power is by the crucifixion of the “old man” by co-crucifixion with Christ.)
APPLICATION: The Spirit’s regenerating work unites us to Christ. An unbreakable union ensues. Because of the believer’s union with Christ, final resurrection is assured (Rom 6:5; 1Cor 15:22; Rom 8:17). We will always be with Him (1Thess 4:17, 18). He who has the Son has the life (1 Jn 5:12).
Being united with Christ saves us from the PENALTY of sin, the POWER of sin, and, ultimately, the PRESENCE of sin. If a person is only interested in being delivered from the penalty of sin, what does it say about the lack of evidence that they are in union with Christ? (Note the passages which teach that Christ purchased the believer’s consecration – 2 Cor 5:14, 15).
APPLICATION: There is nothing that man can do to command or control the new birth. Neither baptism, nor a religious formula, or membership in a church can eternally unite a person to the Son of God. Being united with Christ is an act only God Almighty can perform – it is not even triggered by man’s action (Jn 1:12, 13; Matt 11:27; Eph 2:1-10; James 1:18). (See quote from The Cross and Salvation, by Bruce Demarest on the erroneous view of Catholicism, p. 317.)
IV. The Dimensions of Union with Christ
A. In union with Christ by faith, there is the legal imputation of Christ’s righteousness which is justification by faith (Rom 3:24-26). The Holy Spirit works in the person He is calling a profound awareness of the fact that they have no righteousness of their own. The righteousness with which they must appear before God to be just is the imputed righteousness of Christ.
B. There is the feeling of dependence upon Christ in the depths of one’s being.
The Christian understands that all the grace he receives is from Christ, not from religious practices. The Christian life entails a spiritual or mystical participation in the graces, or qualities of Christ our “Head.” As we behold Him by faith and seek to imitate Him, our souls are renewed in the image of Christ (2 Cor 3:18) (someday bodily! – Phil 3:21).
C. There is a social dimension of union with Christ. The unity of the saints is the result of union with Christ (Phil 2:1, 2ff). The unity among believers is to be a powerful, and practical unity of mind, heart, and will so that God’s loving purpose is seen by the world (Jn 17:21-23; Rom 15:5, 6).
V. The Results of Union with Christ
A. When we have been crucified with Christ, the old anti-God bias and its sinful passions has been put to death so that it is rendered powerless as a dominating force (Gal 2:20). The believer is freed from the yoke of the Law (Gal 2:4). Union with Christ produces sanctification (Gal 5:24; 1 Cor 6:17-20). There will be holy progress, ethical progress. As a necessary consequence of union with Christ, we will gain an increasing knowledge of God. We will be empowered so as to make headway against what remains of our corruptions (Rom 8:12, 13). Eternal life is the outcome of a life of sanctification in Christ (Rom 6:22).
B. Union produces an awareness of God’s presence in the heart (Col 1:27;Rom 8:14-16). There will be an experiential knowledge of God’s love and the Son’s grace, and the Holy Spirit’s consolation and comfort. The believer will take great delight in fellowship with the Father and the Son through the Holy Spirit. Profound spiritual communion is a result of union with Christ (Gen 6:9). There will be godly fear and a profound sense of His presence. Do you think it is possible to be in union with Christ and little desire for fellowship with the Lord? Why or why not?
C. Union produces a heightened sense of dependence upon the Savior for service, for victory over sin, and for the empowerment of our spiritual faculties (Jn 15:5).
D. Union with Christ has an incredible significance for one’s daily walk. Christ is the fountainhead for every spiritual blessing: repentance, faith, pardon, justification, adoption, sanctification, perseverance, glorification (1 Cor 1:30; Rom 8:29-32). No human agency can join us to Christ. Once the Spirit baptizes a person into Christ, the Lord becomes their Head and Husband. To the degree that you take seriously your union with Christ, you will give evidence by your holy walk that you are saved.
Louis Berkhof, Systematic Theology
James M. Boice, Foundations of the Christian Faith
Bruce Demarest, The Cross and Salvation
Wayne Grudem, Systematic Theology
Robert Reymond, A New Systematic Theology