WHAT DOES IT MEAN TO BE “IN CHRIST”? (A Study of Union with Christ Jesus as the Foundation of All Saving Benefits)

There is a phrase that runs through the letters of the Apostle Paul like a golden thread, appearing so frequently that the casual reader can easily pass over it without pausing to weigh its full significance. That phrase is “in Christ”. It appears, in its various forms (“in Him”, “in whom”, “with Christ”, “through Christ”), well over two hundred times in the Pauline corpus alone. Yet for all its frequency, it remains one of the most profound and poorly understood expressions in the whole of Christian theology.

What does it mean to be “in Christ”? Is it merely a manner of speaking, a shorthand for being a Christian? Is it a mystical formula, an invitation to a private, ecstatic communion with the divine? Or does it carry a weight of theological meaning that, once understood, transforms the way we understand salvation, the church, Christian living, and the very structure of God’s purposes in redemptive history?

The answer to that last question is yes. Union with Christ Jesus is not a secondary or decorative doctrine. It is, as the great Scottish theologian John Murray wrote, the central truth of the whole doctrine of salvation. Every spiritual blessing that the redeemed sinner enjoys (election, justification, adoption, sanctification, glorification) flows from and is grounded in the believer’s union with the Lord Jesus Christ. To understand what it means to be “in Christ” is to understand the very heart of the gospel.

This article is an attempt to open up that glorious truth for the people of God. It is not primarily an academic exercise, though it will not shy away from careful attention to Scripture. It is, above all, a pastoral and devotional exploration of one of the most magnificent realities in all of Christian experience.

THE PHRASE ITSELF: A SURVEY OF THE BIBLICAL LANGUAGE

Before we can understand the reality, we must take the language seriously. The Greek phrase that lies behind our English “in Christ” is most commonly εν Χριστῷ (en Christō), which is to say, “in Christ”. The Apostle Paul also uses εν αὐτῷ (en autō, “in Him”) and εν ᾓ (en hō, “in whom”), as well as the compound preposition σὺν (syn, meaning “with”), which generates a whole family of compound verbs: “co-crucified”, “co-buried”, “co-raised”, “co-seated”. These are not casual synonyms. Together they paint a picture of a relationship so deep, so organic, so total, that ordinary human analogies can only approximate it.

Consider just a few of the places where this language appears in its fullness. In Ephesians 1:3–14, the Apostle Paul writes:

“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, just as He chose us in Him before the foundation of the world… In Him we have redemption through His blood, the forgiveness of our trespasses… In Him also we have obtained an inheritance…” (Ephesians 1:3–4, 7, 11, NASB 1995)

The phrase “in Christ” or “in Him” occurs no fewer than eleven times within those twelve verses. Every blessing (election, redemption, forgiveness, inheritance, sealing by the Holy Spirit) is located “in Him”. Outside of Him, there is none of it. Outside of Him, there is nothing.

In Romans 6:3–6, the Apostle Paul writes of believers being baptised “into Christ Jesus”, sharing in his death and resurrection. In Galatians 2:20, he describes the Christian life as one in which “I have been crucified with Christ; and it is no longer I who live, but Christ lives in me”. In Colossians 3:3, the believer’s life is said to be “hidden with Christ in God”. In 2 Corinthians 5:17, “if anyone is in Christ, he is a new creature; the old things passed away; behold, new things have come”.

This is not incidental. This is the very architecture of the Apostle Paul’s theology. The doctrine of union with Christ Jesus is not one tile in a mosaic; it is the frame that holds all the tiles together.

THE NATURE OF THE UNION: WHAT KIND OF UNION IS THIS?

Having established the biblical breadth of the language, we must now ask what kind of union the Apostle Paul has in mind. Three errors must be avoided.

¶ It Is Not a Pantheistic or Ontological Merger

When the Apostle Paul says the believer is “in Christ”, he does not mean that the believer stops to be a distinct person and is absorbed into the divine being. This is the error of mysticism in its more extreme forms, and it is wholly foreign to the biblical text. The believer remains a creature; Christ Jesus remains the Creator and Redeemer. The union is real and organic, but it does not dissolve the distinction between the divine and the human, or between the Saviour and the saved.

¶ It Is Not a Merely Moral or Relational Union

At the other extreme, some have reduced union with Christ Jesus to nothing more than a moral imitation: the believer is “in Christ” in the same way that a student is “in” the teaching of his master: adopting his principles, following his example, committing to his cause. This domesticated account utterly fails to do justice to what the Apostle Paul actually says. The Apostle Paul does not simply say we follow Christ Jesus or agree with Christ Jesus. He says we died with him, were buried with him, were raised with him, and are seated with him in the heavenly places (Romans 6:4–6; Ephesians 2:5–6). This is language of a union far more radical than moral imitation.

¶ It Is a Vital, Spiritual Union

The union the Apostle Paul describes is vital: that is, it is a union of life. It is constituted by the Holy Spirit, Who indwells the believer and joins him to the risen Christ Jesus. The best analogy Scripture itself offers is that of a vine and its branches (John 15:1–5), or that of a head and its body (Ephesians 1:22–23; 4:15–16), or that of a husband and wife who become “one flesh” (Ephesians 5:31–32).

The Westminster Larger Catechism captures this well in Question 66, where it defines the union with Christ Jesus that the elect have as “an inward and spiritual grace… wrought in them by the Spirit of God”; a union that is “mystical”; not in the sense of being irrational or unknowable, but in the sense of being of surpassing depth and wonder, transcending our ability to fully analyse while remaining perfectly real.

It is, we might say, the deepest relationship that exists in all of creation: a bond between the eternal Son of God and His redeemed people, forged in the counsels of eternity, sealed in the blood of the cross, applied by the Holy Spirit in regeneration, and destined to endure through all eternity.

THE DIMENSIONS OF THE UNION: HOW MANY LAYERS DOES IT HAVE?

Union with Christ Jesus is not a simple, single-layered reality. When theologians speak of it, they typically identify several distinct but inseparable dimensions. Understanding these dimensions helps us see the true grandeur of what God has done.

¶ Elective Union: Chosen in Him Before the Foundation of the World

The first dimension is what we may call ELECTIVE UNION. Before time began, before creation was called into existence, before you or I had drawn a single breath, God the Father chose His people in His Son. “Just as He chose us in Him before the foundation of the world”, the Apostle Paul writes in Ephesians 1:4.

This is extraordinary. It means that our union with Christ as did not begin when we believed. It began in the eternal counsel of God. We were not chosen and then placed into Christ Jesus. We were chosen in Christ Jesus: our election and our union with him are not two separate acts but one undivided divine purpose. Before we were, we were His. This is the ultimate ground of the believer’s security: we were loved in Him before we existed.

¶ Federal Union: Christ Jesus as the Representative Head

The second dimension is FEDERAL UNION. In the structure of the covenant of grace, Christ Jesus stands as the federal head (the representative) of his people. Just as Adam stood as the federal head of all humanity in the covenant of works, and his transgression was reckoned to all whom he represented (Romans 5:12–19), so Christ Jesus stands as the second Adam, and His obedience and righteousness are reckoned to all whom he represents.

This is the foundation of justification by faith. When God declares the sinner righteous, He does so on the basis of a righteousness that is not the sinner’s own: it is the righteousness of Jesus Christ, imputed to the believer on account of their union with Him as their covenant head. As the Apostle Paul writes 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 Westminster Confession of Faith, in Chapter XI on Justification, is careful to locate the ground of justification precisely here: “God did, from all eternity, decree to justify all the elect, and Christ did, in the fullness of time, die for their sins, and rise again for their justification” (WCF 11.4). The imputation of Jesus Christ’s righteousness presupposes the federal union between the Mediator and those for whom He acts.

¶ Redemptive-Historical Union: Participation in His Death and Resurrection

The third dimension is perhaps the most electrifying. The Apostle Paul teaches that believers are so genuinely united to Christ Jesus that when He died, they died; when He rose, they rose; when He was seated at the right hand of the Father, they were seated with Him. This is not merely a legal fiction or a convenient metaphor. The Apostle Paul speaks of it as a historical and spiritual reality.

“Or do you not know that all of us who have been baptized into Christ Jesus have been baptized into His death? Therefore we have been buried with Him through baptism into death, so that as Christ was raised from the dead through the glory of the Father, so we too might walk in newness of life.” (Romans 6:3–4)

The Greek verb forms here are crucial. In Romans 6:5, the Apostle Paul uses the perfect passive participle σύμφυτοι (symphytoi, often translated “united” or “grown together”), drawing on a horticultural metaphor of grafting, of two living things joined so completely that they share one life. What happened to Christ Jesus has happened to us, because we are genuinely in Him.

And what happened to Him? He died to sin once for all (the Greek adverb is εφάπαξ (eph’ hapax, “once for all time”, Romans 6:10)) and He was raised in imperishable life, never to die again. Because the believer is in Him, the believer has passed through death and out the other side. Sin no longer has dominion, because death no longer has dominion. The resurrection life of Christ Jesus is the life of His people.

4. Mystical Union: Indwelling Presence by the Holy Spirit

The fourth dimension is the INDWELLING, EXPERIENTIAL UNION constituted by the Holy Spirit. Christ Jesus does not merely stand above us as our representative or outside us as our example. By His Spirit, He dwells within His people. “I have been crucified with Christ”, the Apostle Paul writes, “and it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh I live by faith in the Son of God, who loved me and gave Himself up for me” (Galatians 2:20).

This is the subjective and experiential dimension of union with Christ Jesus: the one most immediately accessible to the believer’s consciousness. It is what makes prayer a real conversation rather than a religious monologue, what makes worship a genuine encounter rather than a performance, and what makes the Christian life something fundamentally different from mere religious observance. Christ Jesus is not merely believed in; He is inhabited. He is not merely trusted; He lives.

UNION WITH CHRIST JESUS AS THE FOUNDATION OF ALL SAVING BENEFITS

John Murray, in his classic work Redemption Accomplished and Applied, described union with Christ Jesus as “the central truth of the whole doctrine of salvation”. This is not hyperbole. Every individual benefit of salvation can be shown to flow from and rest upon union with Christ Jesus.

¶ Justification

The sinner is declared righteous before God not on the basis of any righteousness residing in himself, but on the basis of the righteousness of Christ Jesus, which is reckoned to him by virtue of his union with Christ Jesus as his covenant head. Justification, as the Apostle Paul argues in Romans 3–5, is not the result of works but of faith: and faith is precisely the instrument by which the sinner is united to Christ Jesus, and by which Jesus Christ’s righteousness becomes, before God, the sinner’s righteousness.

¶ Adoption

The believer is made a child of God not in his own right but in Christ Jesus. The eternal Son is the Son by nature; the believer is made a son or daughter by grace, through union with him. “For you are all sons of God through faith in Christ Jesus” (Galatians 3:26). The fatherly love of God toward the believer is the overflow of His eternal love for His Son: and the believer, being in the Son, is caught up into that love. As Jesus Christ himself prayed in John 17:26: “I have made Your name known to them, and will make it known, so that the love with which You loved Me may be in them, and I in them”.

¶ Sanctification

The Holy Spirit Who indwells the believer is the Spirit of Christ, and His work of transformation is nothing other than the progressive conforming of the believer to the image of the One to Whom he is united. Sanctification is, in its deepest structure, a drawing out of what union with Christ as already means: “For those whom He foreknew, He also predestined to become conformed to the image of His Son” (Romans 8:29). The goal of sanctification is conformity to Christ Jesus, and the engine of sanctification is union with Christ Jesus.

¶ Glorification

Even glorification (the final, eschatological transformation of the believer’s entire person, body and soul, at the resurrection) is grounded in union with Christ Jesus. Because the believer is united to the risen Christ Jesus, the resurrection life that is already his as a present spiritual reality will one day be his as a full and bodily reality. “But if the Spirit of Him who raised Jesus from the dead dwells in you, He who raised Christ Jesus from the dead will also give life to your mortal bodies through His Spirit who dwells in you” (Romans 8:11).

From before time, through time, and into eternity: every act of saving grace is an act performed in Christ Jesus, through Christ Jesus, for those who are in Christ Jesus.

PRACTICAL IMPLICATIONS: WHAT DIFFERENCE DOES THIS MAKE?

It would be a mistake to treat this doctrine as a matter of purely theoretical interest. The doctrine of union with Christ has profound and immediate practical implications for Christian living.

¶ The Ground of Assurance

Because the believer’s standing before God rests not on his own performance but on his union with Christ Jesus, assurance is not a perpetual guessing game. The question is not “Am I good enough?” but rather “Am I in Christ?” And the marks of being in Christ Jesus: genuine faith, love for the brethren, a life being transformed by the Holy Spirit, a growing sense of one’s own sinfulness alongside a growing confidence in God’s mercy in Christ Jesus: these are knowable, experienceable realities. The Westminster Confession of Faith, in Chapter XVIII, speaks of a “certain assurance of grace and salvation” that the believer may attain, “without extraordinary revelation”, by attending to the promises of God and the inward evidence of the Holy Spirit’s work.

¶ The Motive for Holiness

Union with Christ Jesus does not lead to moral carelessness: the very thought horrified Paul (Romans 6:2). Quite the opposite: because the believer has been united to the Holy Son of God, and because the Holy Spirit of holiness now dwells within him, holiness is not an external demand but an internal impulse. “For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand so that we would walk in them” (Ephesians 2:10). We pursue holiness not to become accepted, but because we already are accepted, in him.

¶ The Source of Comfort in Suffering

When the believer suffers, he does not suffer alone and he does not suffer without meaning. He suffers as one who is united to a Christ Jesus Who Himself suffered, and Whose sufferings were the ground of the world’s redemption. “Now I rejoice in my sufferings for your sake, and in my flesh I do my share on behalf of His body, which is the church, in filling up what is lacking in Jesus Christ’s afflictions” (Colossians 1:24). The union with Christ Jesus that is the ground of our salvation is also the frame within which our suffering finds its meaning.

¶ The Foundation of Christian Community

The church is not primarily a voluntary association of like-minded individuals. She is the body of Christ Jesus: all her members united to the same head, sharing the same life, animated by the same Holy Spirit. The unity of the church is grounded in the shared union of all believers with Christ Jesus. “For even as the body is one and yet has many members, and all the members of the body, though they are many, are one body, so also is Christ” (1 Corinthians 12:12). Our love for one another is an expression of our common participation in him.

A DEVOTIONAL CLOSING: THE WONDER OF BEING FOUND IN HIM

We began with a simple question: what does it mean to be “in Christ”? We have traced the language through the Scriptures, explored the nature of the union, unpacked its several dimensions, grounded all saving benefits within it, and drawn out some of its practical implications. But perhaps the most important thing to say at the end is the simplest.

It means that you are not alone.

It means that the eternal Son of God, by Whom and for Whom all things were created, Who upholds the universe by the word of His power, Who sat down at the right hand of the Majesty on high: that He is for you, with you, in you, and you are in Him. It means that your past is covered by His blood, your present is sustained by His life, and your future is secured by His resurrection. It means that when the Father looks upon you, He sees you clothed in the perfect righteousness of His own beloved Son.

The Apostle Paul, reflecting on all of this, could come to only one conclusion: and it was not a theological proposition. It was a cry of wonder: “But whatever things were gain to me, those things I have counted as loss for the sake of Christ. More than that, I count all things to be loss in view of the surpassing value of knowing Christ Jesus my Lord, for whom I have suffered the loss of all things, and count them but rubbish so that I may gain Christ, and may be found in Him” (Philippians 3:7–9).

To be found in Him. That is the sum of salvation. That is the substance of the gospel. That is the believer’s life, his hope, his treasure, and his song.

To be in Christ Jesus is to have everything. To be outside of Christ Jesus is, whatever else one may possess, to have nothing at all.

About the Author

Ezekiel Temitope Isaac is a Christian and a passionate expository Bible teacher. He is deeply committed to sound biblical doctrine and devoted to teaching and mentoring others in how to properly read and understand Scripture. He serves as a Bible Teacher in LOGOS Ministry and Ilorin Reformed Baptist Missions, based in Ilorin, Kwara State, Nigeria.