“How do we receive those benefits which the Father bestowed on his only-begotten Son?” Calvin answers by saying we must first “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.”

For English Reformed Orthodoxy, the doctrine of a believer’s union with Christ was paramount. John Owen, enunciating the centrality of a believer’s union, exclaimed that our union with Christ is the “principle and measure of all spiritual enjoyments and expectations.”^[1]  Likewise Thomas Goodwin expressed a similar conviction that “being in Christ, and united to him, is the fundamental constitution of a Christian.”^[2] It is a bit surprising then when one looks at the Westminster Confession of Faith, that high-water mark of Puritan theological codification, where we find no chapter expressly dedicated to the doctrine of union with Christ. But this in no way means the doctrine is not there. No, it runs like a silver thread throughout the document underlying much of the theology laid out in its pages.

Perhaps the clearest place to see the doctrine is in the Shorter Catechism question 30, which asks “How doth the Spirit apply to us the redemption purchased by Christ?” The answer: “The Spirit applieth to us the redemption purchased by Christ, by working faith in us, and thereby uniting us to Christ in our effectual calling.” The language used here harkens back to Calvin’s famous passage on union with Christ in his Institutes where he asks the same question. “How do we receive those benefits which the Father bestowed on his only-begotten Son?” Calvin answers by saying we must first “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.”^[3]

Calvin is getting us to see the absolute need a sinner has to be found in Christ. Indeed, this “problem” of how a sinner partakes of the benefits of salvation found in the person of Jesus Christ lies underneath the title to John Murray’s book Redemption Accomplished and Applied. We can agree that Jesus accomplished salvation in his person and at a particular point in time. The question that arises though is how that salvation is applied to sinners before or after the historical events of Christ’s life, death, and resurrection. The answer lies in the doctrine of a person’s union with Christ.

Let’s see some important ways in which the Westminster Confession and its subsequent Catechisms unpack this doctrine.

It shouldn’t surprise anyone familiar with the reformed theology of the Westminster Confession that the doctrine first arises when discussing God’s Eternal Decrees. In paragraph five we read, “Those of mankind that are predestinated unto life, God…hath chosen, in Christ, unto everlasting glory.” The Scripture referenced for this is Paul’s words in Ephesians 1:4: “He chose us in him before the foundation of the world, that we should be holy and blameless before him.” Here the focus is clearly on our being chosen in the person of Christ. This is what many Puritans referred to as our “immanent union in Christ”, a union grounded in God’s eternal election.^[4]

But this still leaves open the question of how a person actually becomes united with Christ in time. There are many elect persons who have not yet been effectually called and are therefore still, as unbelievers, under the wrath of God. Paul himself seems to get at these two senses of our union in Christ, one immanent, the other actual, when he writes, “God, who saved us and called us to a holy calling, not because of our works but because of his own purpose and grace, which he gave us in Christ Jesus before the ages began, and which now has been manifested through the appearing of our Savior Christ Jesus, who abolished death and brought life and immortality to light through the gospel” (2 Tim. 1:8-10).^[5]

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