Augustine spoke of the totus Christus, or the “whole Christ.” In saying this, he referred to the fact that Jesus and his church are in some ways inseparable, as husband and bride, head and body. Believers are both individually and corporately united to Jesus, and when the church is persecuted, Jesus is persecuted (Acts 9:4). He is in us and we are in him.
It is possible to stretch this imagery too far; it is a union and not an identity. And the church is utterly incomplete without Jesus, while the reverse is not true. Yet there are many applications we can draw from this.
First, this helps us to understand the doctrine of imputation. If the church is united to Jesus as body to head, then we as believers are brought into Jesus’s own obedience and death. We are actually made to be “in him” in his life and death and resurrection. Amazingly, in his death, Jesus chose to be united with us but separated from the Father. What love!
Second, it helps us to make some sense of Scripture’s speaking of being in Christ. Part of this is a spiritual reality. But part of it must be realized in the flesh by our participating in Christ’s church, his body. We cannot enjoy, experience and know the whole Christ if we seek to do so apart from his body the church. We must have a complete head-and-body relationship with Jesus. This also gives us a glimpse into one of the purposes of baptism. If we are baptized into Jesus (Romans 6:3), then part of that means that we are brought into his body, the church.
Third, this gives us a deeper understanding of the imagery of the Lord’s Supper. It is clear that the bread and wine represent Jesus’s body and blood. But we can understand Jesus’s body in two ways — his physical body, and his body the church. It seems that Paul has both of these senses in mind when he writes of the bread and body in 1 Corinthians 10-11. He links the one loaf of bread to the unity of Jesus’s church-body. And when he writes of “discerning the body,” I believe he is primarily concerned that we discern the body as the church, eating the Supper with love and preference for one another. We eat the Supper in a way that reflects the unity we have in the gospel. And in the following chapter, Paul elaborates even further on the image of the church as a body, emphasizing that we must walk in honor and preference and care for one another.
Finally, this reminds us that one of the ways that Jesus is with us to the end of the age (Matt 28:20) is through his church, through our shared life with one another. We enjoy his presence through his word and his Spirit, but also through his body.