“In Christ” is one of Paul’s favorite phrases. A parallel phrase he uses is “with Christ”. Both of these phrases are his shorthand for union with Christ. This is undeniably one of the most important theological concepts in the Scriptures, for our salvation is “in Christ”. Yet, this subject has been largely ignored by theologians for over 100 years. The contemporary church is much weaker as a result of the neglect of this foundational doctrine.
There have been a much needed spate of books that have sought to address this weakness and restore this doctrine to its rightful place in our minds and hearts. That this took so long reveals one of the weaknesses of the current state of publishing. Even Christian publishers are too focused on sales at the expense of needed truth. Thankfully, some smaller publishers have been acting contrary to common practice.
One of the authors of these books is Robert Letham. I must confess that I had not read any of his books, nor owned any until this past year. Now I own three of his books, including Union with Christ: In Scripture, History, and Theology. It shares its subtitle with his book on another neglected subject, the Trinity. The other work of his I recently purchased and began to read is on the also neglected Work of Christ (part of the excellent Contours of Christian Theology series).
Letham, for those unfamiliar with him, is the Senior Lecturer in Systematic and Historical Theology at Wales Evangelical School of Theology. He has advanced degrees from Westminster Theological Seminary and the University of Aberdeen. The book has an academic feel to it, and I was intellectually stretched while reading much of it. This is not a bad thing, people. This is not a fluffy topic, but one that requires rigorous thinking in addition to the illumination of the Spirit to grasp.
I was well rewarded for my efforts. This book is only about 140 pages long, but it is a dense 140 pages. It is full of meat as he grapples with the topic at hand. True to the subtitle, Letham examines Scripture, the history of the Church and theological formulations to help us understand and apply this most important subject. The importance of this subject is evidenced by how many doctrines Letham addresses in the course of examining it: creation, incarnation, the atonement, justification, adoption, resurrection, sanctification etc.
“Because man was created in the image of God, he was made for communion with God, to rule God’s creation on his behalf.”
Letham begins with creation, which surprised me. But since Jesus is the 2nd Adam, this is the best place to begin. Humanity’s communion with God was destroyed by the first Adam’s sin. Jesus would become man in order to restore this communion, and be the means of that communion. So you see that the book takes a few unexpected twists (I’ll be interested to see how the other books I’ve picked up on the subject work thru this). He spends a chapter on the Incarnation, surveying the development of the doctrine. The Eternal Son united himself with human nature, joining Himself with humanity in order to secure our salvation. In salvation, He then unites Himself with the elect as the means of their salvation thru the Spirit. We only partake of the benefits of salvation if we are so united to Him. This is one of the tougher chapters since it grapples with the nature of the hypostatic union. He traces its development through the ecumenical councils and expressions by Athanasius, Cyril, Nestorius and others. He also shows how this is not neglected by the Westminster Confession of Faith but expressed most often in the Larger Catechism.
Letham next explores the work of the Spirit, who is the means of our union with Christ. During His earthly ministry, Jesus relied upon the Spirit. If Jesus, in His humanity relied upon the Spirit so much more must we as fallen but redeemed people rely upon the ministry of the Spirit.
“Since the Spirit unites us to Christ through faith, Christ’s substitutionary and representative work is effected for us and consequently in us.”
From there Letham moves to its connection with Federal Theology- Jesus as our Covenant Head. All are born united to Adam and under guilt and condemnation. Our salvation is found in being united to a new covenant head, the 2nd Adam, by faith. This faith was purchased by Christ and given to us by the work of the Spirit. Here Letham surveys the development of this thought in Calvin, Zanchius, Polanus, Goodwin and the Westminster Confession of Faith. He explores its connection with justification and contrasts the Reformed understanding with the Lutheran formulations.
One of the more interesting chapters was the one transformation. He addressed the idea of sanctification as theosis, or deification. Here he draws on his studies of Eastern Orthodoxy (see Through Western Eyes for more). This is often misunderstood by the Western church. He explores this theme, and shows how the same idea is found in Augustine, Aquinas and Calvin. We do not partake of Christ’s divinity, but are conformed to His character in sanctification. As we partake of this union with Christ we become like Christ. Our salvation has both legal and transformational dimensions. Here he also discusses sacramental theology, and why the Reformed understanding of communion is different than the others. It is by virtue of our union with Christ’s humanity that we “feed” upon Christ. It is not Christ inhabiting the elements, but our fellowship with Him by the Spirit. This is, by far, the longest chapter.
The final chapter discusses its connection with the resurrection- Christ’s and ours. Our union with Christ is not dissolved at our death. It continues as we are with Christ awaiting the resurrection and consummation.
This is a great little book, but it may not be for everyone. It can be difficult reading. But it is important reading. One reason this subject has fallen out of vogue, he theorizes, is the influence of Scottish Common Sense Realism in the theology of men like Charles Hodge. This is a topic difficult to describe, much less understand, when under the influence of that philosophical viewpoint. It is time to recapture what the church believed and taught about this very important subject. Letham does much to assist us in this process.