Union With Christ (with Tom O’Toole)

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Union With Christ Is An Important But Neglected Truth

  • It is familiar to many of us, but isn’t always in the front of our minds as we engage with the Bible.
  • This truth is a cornerstone of New Testament We don’t talk about it nearly as often as the New Testament authors do.
  • There are 216 references to union with Christ in Paul alone (including 83 occurrences of the exact phrase ‘en Christo’).

“Nothing is more central or basic than union and communion with Christ… Union with Christ is really the central truth of the whole doctrine of salvation, not only in its application but also in its once for all accomplishment in the finished work of Christ.” (John Murray)

What Is Union With Christ?

  • Union with Christ is representative headship.
  • Our first representative head was Adam, and by his disobedience we were all made sinners (see Romans 5:19).
  • This is illustrated in the case of Abraham and Levi. Hebrews 7:9-10 suggests that Levi gave a tithe to Melchizedek because he was ‘in Abraham’ at the time.
  • Jesus is compared with Adam as another representative head (Romans 5:17).
  • If we are united with Christ, we share in his death and resurrection (Romans 6:3-5).

“So Christ died in our place and suffered where we did not. But he was the last Adam, the head of the new humanity, and therefore just as all who are born in Adam share in Adam’s fate, so all who are reborn are in Christ share his. All who are members of Christ’s body experience what happened to that body. We died with him. Our old identity was slaughtered, speared and buried with Christ (Colossians 2:12; Romans 6:13). His death, not our sin is our past.” (Mike Reeves)

  • Union with Christ is personal identification.
  • This is a similar idea to representative headship, but applied in reverse.
  • Jesus identifies with his people, and takes personally the way we are treated (see Acts 9:40 and Matthew 10:40).
  • Union with Christ is life-giving connection.
  • In John 15 Jesus teaches that he is the vine and we are the branches. It is only in him that we are able to bear any fruit.
  • Union with Christ is a reproducible identity.
  • ​Christ is described as the first fruits and we are like seeds in him that will grow after his likeness.
  • In 1 Corinthians 15:20-23, this is applied to the resurrection. He was the first to experience it, but all who are in him will also be made alive.
  • This idea can also be applied to character development and the fruit of the Spirit. The same characteristics that Jesus perfectly embodied will becoming increasingly prominent in our own lives.
  • Union with Christ is an experiential relationship.
  • It is not an abstract theory, but something that we can experience and enjoy (see Philippians 3:8-11 and Ephesians 3:14-19).

The Cascading Extension of the Trinity

“The central reality of the Christian life is that believers are united to Christ, and the reason this is so central is that it links us to the central relationship that there is, Christ’s relationship to his Father.” (Donald Fairburn)

  • The relationship that believers have with Christ is likened to Christ’s relationships with his Father in passages such as John 17:22-23 and 1 Corinthians 11:3.

“To say that our union with Christ is Trinitarian means that by virtue of being incorporated into the life of Jesus Christ, we participate in the life, love and fellowship of the Trinity. Because the Son is one with the Father, our being joined to the Son means we are joined to the Father. And because the Spirit exists as the bond of communion between the Father and the Son, he brings us into that community by uniting us to Christ. This staggering Biblical revelation forms the personal foundation for all the benefits that constitute our salvation.” (Marcus Peter Johnson)

Union With Christ Is Crucial For Our Theology to Work

  • Creation– All things were made through and for Jesus (see Colossians 1:16).
  • Providence– In Jesus, everything holds together (see Colossians 1:17).
  • The Church– Just as the relationships of the Trinity cascade into our union with Christ, so they also cascade into our relationships with one another (see John 17:20-23). The church is the people that is in Christ (see Ephesians 2:20-22 and 3:10-11).
  • The Justice of God– The answer to ‘how can God be just and still forgive sinners?’ lies in our union with Christ (see Proverbs 24:24 and Romans 3:21-26).
  • Salvation– Every part of our salvation makes sense ‘in Christ’. Notice how often the phrase is used in Ephesians 1. We are adopted in Christ, forgiven in Christ, sealed in Christ, sanctified in Christ, we persevere in Christ, we are resurrected in Christ and we are glorified in Christ.

“First, we must understand that as long as Christ remains outside of us, and we are separated from him, all that he has suffered and done for the salvation of the human race remains useless and of no value to us. Therefore, to share in what he has received from the Father, he had to become ours and to dwell within us… for, as I have said, all that he possess is nothing to us until we grow into one body with him.” (John Calvin)

  • Jesus’ Priesthood– Jesus can truly represent us as a priest because of our union with him (see Hebrews 2:14-17).
  • Eschatology– Ephesians 1:9-10 tells us that all things are being brought together ‘in Christ’. We will experience our coming resurrection in Christ. Understanding our union with Christ transforms the resurrection of Jesus from the vindication of a good man to a eucatastrophic moment that reverses the trajectory of the cosmos.

Union With Christ Is Crucial For Our Christian Lives

  • Union with Christ is experiental by nature. It renders ‘abstract Christianity’ nonsensical.
  • Union with Christ is game-changingly transformational. Being brought out of Adam and into Christ changes everything. Bearing fruit is the norm (see John 15 and 1 Corinthians 6:15-17).
  • Union with Christ is identity shifting.Who we are has changed. We are no longer called sinners but saints (see 2 Corinthians 5:17 and Romans 6:11).
  • Union with Christ is positively affirming.
  • Union with Christ is purpose defining(see Galatians 2:20).


  1. How important is it to communicate a deep understanding of unity with Christ when you are explaining the gospel to a non-Christian?
  • It depends on who you are talking to.
  • For some people it will be helpful and may help them to make sense of some of their questions.
  • For others, a deep explanation wouldn’t help.
  • It is important to keep the idea in there, but the depth to which you explain it will vary.
  1. Can you explain a bit more about the distinction between being a saint and sinner, particularly regarding the emotional conflict that you feel when you do something wrong?
  • It is helpful to bear in mind the Mike Reeves quote that Jesus’ death, not our sin, is our past.
  • In the Psalms it talks about our sin being removed ‘as far as the East is from the West’.
  • Often when we sin, we want to sit under it and feel guilty for a while. The visual image of ‘as far as the East is from the West’ can make us ask why we are holding on to it.
  1. Can you go into more depth about why the baptism of Jesus is necessary in the incarnation?
  • The baptism was symbolic of something that was necessary – Jesus identifying with us.
  • In order for Jesus’ work to be applied to us, he needs to be able to truly represent us as a man.
  • In baptism, Jesus was standing in the rivers with sinners even though he wasn’t one – he was saying, ‘I am with you’. He said to John the Baptist that the baptism was fitting to fulfil all righteousness.
  1. What does it means that Jesus is the last Adam?
  • He is our representative head, just as Adam was.
  • A representative is someone who takes a role on behalf of a group. For example, when David fought Goliath, he was representing the whole people and they would all share in his success or failure.
  1. How do you abide/remain in Christ ?
  • John 15 talks about 2 truths simultaneously – there is a responsibility on us to bear fruit or we will be taken away (verse 2) and if we abide, we will bear fruit (verse 5).
  • It starts with abiding – abide, bear fruit, therefore don’t be taken away.
  • There is the same tension in other New Testament passages. This can be easier to square when looking at it from the end of history. Those that didn’t stay the course were in some way not in Christ.
  • John and Paul use the phrase ‘in Christ’ in different ways.
  • In terms of how we abide in Christ, we need to focus on the relationship we have with him and guard against our Christianity becoming abstract. It’s easy to start faking it. We will each know inside how genuinely we are realting to Jesus. Be part of the community that is the church. When you remove yourself from church it is usually not long before you stop walking with Jesus.
  1. Do we preach enough about our responsibilities in being in Christ?
  • There has been a trend recently towards speaking more about our freedoms and less about our responsibilities.
  • It is important not to swing too far the other way.
  • When Jesus spoke to people who were far from God, he placed a lot of emphasis on freedoms and not much about responsibilities.
  • But then as people started following him, he took years with them, teaching and instructing them in a life-on-life way.
  • Perhaps there is a place for talking about responsibilities more, but the bigger piece that we are lacking is mentorship and discipleship.