I can think of three answers to that question. First, we must confess that the doctrine suffers from a degree of inevitable abstraction that makes it hard to comprehend. Not all truth is easy. Not every doctrine can be reduced to 140 characters. Sometimes, our best efforts notwithstanding, we remain frustrated by an element of profound mystery. And while recognizing the limits of our understanding and the profundity of the doctrine ought to mitigate our frustration as we wrestle with this teaching, union with Christ, because it is a difficult idea, is often overlooked in preaching and in the regular course of Christian discipleship in favor of more familiar and easier-to-explain doctrines.
And that leads to the second reason for our neglect of this truth. In the history of evangelical preaching and catechesis, union with Christ has not received the attention it deserves. Justification by faith alone, the necessity of the new birth, the call and obligation of sanctification, the inerrancy of Scripture, the doctrine of God—all these have occupied the attention of evangelical churches since the Reformation. Sometimes this dynamic is driven by contemporary threats to orthodoxy. Sometimes during seasons of revival, particular truths quite appropriately receive special emphasis. There are good reasons for the focus on each of these vital doctrines in church history. But a simplistic reading of the past can lead to a formulaic presentation of truth in the present. That’s how vital doctrine gets left on the shelf.
A third reason why union with Christ is often neglected, I suspect, has to do with the scope of the doctrine. Unlike other components of the biblical teaching on Christian salvation, union with Christ cannot be identified with any one link in a chain of saving blessings communicated to sinners who come to trust in Jesus. We may have become accustomed to thinking about the ordo salutis (order of salvation) as a way to describe the logical order of God’s various acts and works in the application of redemption. Seminarians learn it as an outline in preparation for ordination exams. We speak of effectual calling and regeneration, faith and repentance, justification, adoption, and definitive and progressive sanctification. We might add the believer’s perseverance and conclude with the great truth of future glorification. Unquestionably, there is great value in mastering that outline. But where should we place union with Christ?
According to Paul, the “God and Father of our Lord Jesus Christ . . . has blessed us in Christ with every spiritual blessing in the heavenly places” (Eph. 1:3, emphasis added). We are united to Christ in the election of grace in the eternal counsels of God. We are united to Christ at the cross when Jesus died for sinners as our representative and substitute. We are united to Christ in our experience when we are born again from above by the Holy Spirit. We are justified in Christ, adopted in Him, sanctified in Him, glorified in Him. Union with Christ, to return to the analogy with which we began, is the country within which every facet of the believer’s new life and identity becomes his. It is the environment for every spiritual blessing. It cannot be located at any one point but must be woven through the whole fabric of Christian teaching about the way God saves.
Union with Christ is a vast, comprehensive, glorious truth. It is well beyond the scope of six articles to explain. And yet, as we may have already begun to see, despite its relative neglect, it is precious truth. It is like a pair of tinted spectacles through which we are to view the world. Everything is colored by it; nothing is unaffected by it. In this series, I hope to show how viewing the scope of our salvation through the lens of union with Christ helps us avoid some dangerous pitfalls and leads us to appreciate anew the beauty and glory of Christ Himself, who is the gift of God to all who believe.