Union with Christ: In Scripture, History, and Theology, by Robert Letham. Phillipsburg, NJ: P & R, 2011, 164 pages, $17.99, paper.

Union with Christ: Reframing Theology and Ministry for the Church, by J. Todd Billings. Grand Rapids, MI: Baker, 2011, 180 pages, $19.99, paper.

Union with Christ is one of the current hot-topics across the academy, in exegetical, theological, and historical studies. Hence it should not surprise readers to find new books on this subject. Two recent entries are those offered by Robert Letham, senior lecturer in systematic and historical theology at Wales Evangelical School of Theology, and J. Todd Billings, associate professor of Reformed theology at Western Theological Seminary. Both books treat the doctrine of union with Christ but from slightly different perspectives. Letham offers a systematic survey of union, while Billings builds off of his earlier work on Calvin’s doctrine of union and addresses both doctrine and issues related to the ministry of the church.[1] Letham’s book has six chapters that treat union and creation, the incarnation, Pentecost, representation, transformation, and the resurrection. Billings’s book originally began as a series of lectures and goes beyond introductory matters; he covers union as it relates to adoption, a better understanding of total depravity, communion with God, the gospel and justice, and a critique of incarnational models of ministry. Both books are worthwhile reads but for different reasons.

Positive Qualities

Letham’s book offers several positive qualities that commend his work. Readers are given helpful analyses of a number of historical sources, including authors and ideas from the patristic, early modern, and contemporary periods. Such research opens vistas upon the doctrine of union that present day readers might not otherwise explore. And contrary to current trends in the North American Reformed context, Letham rightly holds the compatibility of union with Christ and the ordo salutis; he argues that these two ideas are bound together in the Westminster Standards (88–90). And one of the refreshing aspects of Letham’s approach is that he encourages readers to construct the doctrine of union upon the whole canon of Scripture, not simply the writings of Paul, as has been the trend among some theologians (91). Letham also offers a helpful contribution that will likely benefit present discussions and debates about union with Christ. He begins his book, not with the application of redemption, but with creation, and more specifically the incarnation of Christ. He rightly acknowledges that the basis of the believer’s union with Christ lies in the incarnation (21).

Billings offers some unique contributions that make his book worthy of study. His treatment of adoption as a key element of union is stimulating; adoption is one of the more underappreciated doctrines because historically a number of Reformed theologians have considered it as part of justification rather than placing it among the other relative benefits of union with Christ. Billings’s emphasis upon praxis is also a welcome contribution as most discussions about union focus upon the ontology of the “what and when” of the alpha-point of union and the relationship between justification and sanctification. As important as these subjects are, and they are vital, ruminating upon union as the basis of the believer’s communion with the triune Lord through the means of grace is a much appreciated and needed reminder of the fount of the Christian life (63–94). Billings also offers a potent alternative to the “religious left wing’s” call to social action and the “religious right’s” view that justice for the poor and marginalized of society is merely an optional add-on for the Christian life (95–96). Since the double benefit of union is both justification and sanctification, it means all Christians should seek to manifest good works to all, not as personal achievement but as the fruit of their union with Christ (107–8). Markedly, Billings does not argue for “social justice,” an ill-defined political idea where certain classes of individuals, such as the poor, are singled out as the special recipients of the church’s activity. Rather, he contends that justice must be defined Christologically and pursued in union with Christ (115). In other words, as the church preaches, teaches, and administers the sacraments, it always does so with an eye to bringing the cup of cold water to anyone it encounters, not just the poor.

Areas for Further Reflection

Letham’s book provides several areas for further consideration. The first deals with his overreliance upon Calvin to set the trajectory for his discussion about union. True, Letham does engage with other theologians and sources such as Polanus, Goodwin, the Westminster Standards, Bavinck, Stedman, and Zanchi, but these figures and documents feature somewhat incidentally compared with the amount of space Calvin receives. Several notable works fail to appear that would add greater depth, texture, and different nuances, such as Zanchi’s work on union with Christ, which was a separately published doctrinal locus extracted from his Ephesians commentary.[2] Zanchi also wrote a personal confession of faith that was intended to replace the Second Helvetic Confession where he discusses soteriology all under the rubric of union with Christ.[3] Also absent is Edward Polhill’s work, Christus in Corde: or, the Mystical Union between Christ and Believers (1680). Equally noteworthy is the nonappearance of Herman Witsius’s Irenical Animadversions (1696) wherein he entered the infamous so-called Antinomian controversy that occurred in England and addressed a number of issues directly related to union, justification, and sanctification.[4]

The lack of interaction with principal primary sources is evident at two other places where Letham offers comments based upon the suspect claims of secondary literature. For example, Letham asserts that for Lutherans union with Christ follows as the effect of justification, a common mantra among certain writers but easily disproved by reference to Lutheran theologians such as Luther and Melanchthon. In his 1535 commentary on Galatians Luther makes regular appeal to union and argues that Christ is present in faith; in other words, union with Christ and faith are concomitant realities—union does not follow as the effect of justification.[5] The same may be said of Melanchthon in two of his refutations against Andreas Osiander, documents that heretofore have not been referenced by those who claim a great divide between Lutheran and Reformed versions of union.[6] Secondary literature such as Olli-Pekka Vaino’s Justification and Participation in Christ has noted that there are at least a dozen different iterations of the so-called “Lutheran” doctrine of justification, and as such, abundant variations as justification relates to union.[7] Just as there is no monolithic doctrine of union among the Reformed, the same can be said of Lutheran theology. Claims of significant difference between the Reformed and Lutheran doctrines of union should be supported from specific primary source evidence.

Based upon secondary literature alone Letham also claims that under the Princetonians, such as Charles Hodge, union with Christ “suffered eclipse” (122). Yet from Hodge’s own testimony taken from an address entitled “The Unity of the Church Based on Personal Union with Christ,” he states: “There is no doctrine of the Bible, more clearly, frequently, or variously taught than this.”[8] In a sermon on the unity of the church, Hodge, like his Reformed predecessors, outlines the two benefits of union, justification and sanctification. But Hodge goes beyond this basic affirmation and, much like Letham, writes of communion, security, and glorification as the effects of union with Christ.[9] In his Romans commentary Hodge affirms that union with Christ is the only source of the believer’s holiness.[10] And a cursory reading of Hodge’s Systematic Theology, and notably his commentary on Ephesians (esp. 5:25–32), effortlessly reveals union did not suffer eclipse in Hodge’s theology.[10] In fact, like Letham, Hodge contends that the believer’s union with Christ rests upon the incarnation of Christ: “Besides, so far as the mere assumption of human nature is concerned, it is a bond of union between Christ and the whole human race; whereas the apostle is here speaking of a union with Christ peculiar to his people.”[11] So, if union suffered eclipse, someone forgot to tell Hodge about it.

A second area of consideration appears in the lack of any discussion of the pactum salutis. Seldom, if at all, have present debates considered this doctrine in relation to union, but in the seventeenth century union and the pactum featured quite commonly. Despite Letham’s criticisms of the doctrine, as a matter of historiography, any treatment that attempts to discuss the history of the Reformed doctrine of union should interact with the different ways that theologians have expressed the doctrine.[12] In this particular case, Reformed theologians such as Turretin, Witsius, Owen, Gillespie, Rutherford, and others employ the pactum as the context in which the incarnation and Christ’s union with believers is decreed and unfolded.[13]

A third area lies in the disproportionate amount of space Letham spends trying to convince readers of the compatibility between union with Christ and the Eastern Orthodox doctrine of deification or theosis. He employs some twenty-four pages (91–115) to show the compatibility between union and deification seeking to cross-fertilize the two traditions as a way to advance the discussion in Western theology (91). Letham correctly notes that not all forms of deification entail the ontological mixture of the essence of the believer with the godhead (99). Yes, there are similarities between union with Christ and deification, but to highlight similarities without noting the differences is unhelpful. For example, Letham rightly refers to the double grace of justification and sanctification as constituent elements of a Reformed doctrine of union. But on the other hand, he fails to mention that Eastern Orthodoxy has no doctrine of justification. This is something that Eastern Orthodox theologians have themselves admitted: “Byzantine theology did not produce any significant elaboration of the Pauline doctrine of justification expressed in Romans and Galatians.”[14] What a theologian or tradition affirms about salvation is equally as important as what it denies. Any attempt to prove the compatibility of theosis and union must take this substantial difference into account.

In this case, there seems to be a fundamental incompatibility between theosis and union given the absence of the doctrine of justification in common Eastern Orthodox formulations. Remonstrants, Socinians, Lutherans, and Roman Catholics all affirmed union with Christ, and more broadly the same can be said about union with God for Judaism, Islam, and Greek philosophers such as Plato.[15] Recall Paul’s famous quotation of Epimenedes (ca. 600 BC) at Mars Hill: “In him we live and move and have our being” (Acts 17:28)—note the “in him” language, reflective of the idea of union with God. Whatever similarities there might be among variants of union with Christ or participation in the divine nature in Christian and pagan theologies, they all melt away beneath the withering heat of the biblical necessity of a forensic doctrine of justification by faith alone in Christ alone through the imputed active and passive obedience of Christ. Everyone affirms union with God, but the devil, and the truth, is all in the details.

A fourth consideration is that Letham avoids current debates about union with Christ almost entirely. This will undoubtedly disappoint some readers as many are looking for clarity and assistance wading through challenging issues. On the one hand, an author certainly has the right to bypass debate (82). On the other hand, it is therefore best to leave all reference to the debate out of the book. But at one point Letham levels the accusation that one author affirms that believers only have “participation in the energies of Christ” (127); he elsewhere characterizes such a view as only being united to the work of Christ rather than his person (cf. 92). To level such a claim without significant exposition and argumentation only elicits more questions and does not prove beneficial.

In Billings’s work there is one area for further reflection regarding the doctrine of adoption. In a number of places Billings refers to adoption as a metaphor (18, 19, 21, 27n28). There are certainly a host of metaphors used throughout the Scriptures to convey ideas related to the salvation of sinners. Jesus, for example, calls himself a “door” by which people must enter in order to be saved as well as a “shepherd” and his people “sheep” (John 10:9, 11). In his teaching Christ compares himself to a vine and believers as branches (John 15:1–6), and Paul likens union with Christ to donning the “armor” of God (Eph. 6:11–18). Each of these ideas legitimately falls into the category of metaphor, where a figure of speech is applied to something else in a non-literal fashion.[16] Jesus is not literally a door, we are not literally sheep, and to be in union with Christ does not mean we put on Kevlar body armor. But is adoption merely a metaphor? Billings writes: “The God of the Bible has no ‘natural’ or ‘begotten’ children apart from Jesus the Son; all the rest of us need to be adopted” (16). This is a true and accurate statement, but he then goes on to characterize adoption as a metaphor, which if strictly applied means that believers are not literally God’s sons and daughters.

In one sense Billings employs a common assumption; characterizing various aspects of the order of salvation as metaphors is a recent widespread phenomenon. To wit, Billings cites Trevor Burke’s work, which is entitled Adopted into God’s Family: Exploring a Pauline Metaphor (18n6).[17] Numerous exegetes and theologians now refer to justification as a metaphor as well.[18] By way of contrast, historic Reformed theology refers to justification as an “act” of God.[19] Part of the contemporary motivation behind calling justification a figure of speech is that the Bible has many different metaphors for salvation and no one image fully expresses the breadth and depth of our redemption. Hence, while one may choose to highlight the forensic metaphor of justification, others may choose instead to employ other metaphors, such as adoption, or union with Christ. We are told that the abundance of metaphors affords greater doctrinal flexibility and facilitates ecumenism because, though Protestants focus upon justification and Roman Catholics transformation, each affirms the same redemptive reality but from different perspectives. What once bitterly divided the Reformation from Rome can be bridged by the proper recognition of the interchangeability of these different metaphors.

To be clear, Billings does not employ the idea of “doctrine as metaphor” anywhere in his book to soften or undermine any aspect of the order of salvation. However, it does appear that he employs the concept uncritically. If adoption is a metaphor, then argumentation to convince readers of the propriety and desirability of such an idea would be helpful, though admittedly such a concern lies beyond the scope of Billings’s work. But in my judgment, adoption is not a metaphor but rather one facet of the rich redemption we have in Christ. We share in Christ’s identity as God’s only begotten Son through union with him; which is a conclusion, I believe, that Billings promotes in his book (e.g. 16–17, 31). If Jesus is metaphorically God’s “son,” then, yes, we are metaphorically God’s “children.” But if Jesus is God’s Son (cf. Ps. 2:7a), then we truly are God’s adopted children, an adoption we receive through union with the only begotten Son. The Shorter Catechism defines adoption in this manner: “Adoption is an act of God’s free grace, whereby we are received into the number, and have a right to all the privileges of, the sons of God” (question 34). Such an expression, I believe, more accurately expresses and defines the nature of adoption; which is a conclusion, I suspect, that Billings would wholeheartedly embrace.


For anyone interested in the doctrine of union with Christ, both books should be read as they investigate different features of union and do so in an engaging and thought-provoking way. These books will undoubtedly stir healthy discussions and whet appetites for further investigation into this wonderful doctrine. However, one thing I hope to see in future discussions is a broader engagement of union beyond the confines of Calvin’s Institutes. As helpful as Calvin is, he is but one star in a galaxy of Reformed luminaries that beam light upon our path. Happily, in the historic Reformed tradition no one luminary serves as a lodestar, but rather each star within broader constellations offers assistance in our collective understanding of our one guiding light, Christ revealed in Scripture. To this end, Billings’s call for theological retrieval offers great promise. With such a strategy the Reformed church can benefit from the wealth of its tradition and learn from many others who have written beautifully and arguably more deftly and skillfully than Calvin. In the words of G. K. Chesterton: “Tradition means giving votes to the most obscure of all classes, our ancestors. It is the democracy of the dead. Tradition refuses to submit to the small and arrogant oligarchy of those who happen to be walking about.”[20] Indeed, the Reformed church can greatly benefit from a theological “democracy,” an appeal to the people (that is, a host of theologians), in its study of union with Christ rather than the artificial imposition of the “monarchy” of Calvin, something our tradition has historically eschewed.


[1] Cf. J. Todd Billings, Calvin, Participation, and the Gift: The Activity of Believers in Union with Christ (Oxford: Oxford University Press, 2007).

[2] Girolamo Zanchi, An Excellent and Learned Treatise of the Spiritual Marriage between Christ and the Church (Cambridge: 1592); idem, Commentarius in Epistolam Sancti Pauli Ad Ephesos, 2 vols., ed. A. H. Hartog, Bibliotheca Reformata, vol. 5 (Amsterdam: 1888).

[3]Girolamo Zanchi, De religione Christiana Fides – Confession of Christian Religion, 2 vols., eds. Luca Baschera and Christian Moser (Leiden: Brill, 2007).

[4] Herman Witsius, Animadversiones Irenicae (Utrecht: 1696); idem, Conciliatory, or Irenical Animadversions on the Controversies agitated in Britain, under the Unhappy Names of Antinomians and Neonomians, trans. Thomas Bell (Glasgow: W. Lang, 1807).

[5] Martin Luther, Lectures on Galatians 1535, in Luther’s Works, vols. 26–27, ed. Jaroslav Pelikan (St. Louis: Concordia, 1963), 26.57, 129, 132–33, 167–68, 352.

[6] Philip Melanchthon, “Iudicium de Osiandro 1552, no. 5017” (Corpus Reformatorum 7.893–97); idem, “Confutation of Osiander (Sept 1555),” in Documents from the History of Lutheranism 1517–1750, ed. Eric Lund (Minneapolis: Fortress, 2002), 208 (Corpus Reformatorum 8.582); cf. Lowell C. Green, How Melanchthon Helped Luther Discover the Gospel (Fallbrook, CA: Verdict Publications, 1980), 230–31.

[7] Olli-Pekka Vainio, Justification and Participation in Christ: The Development of the Lutheran Doctrine of Justification from Luther to the Formula Concord (1580) (Leiden: Brill, 2008), 1.

[8] Charles Hodge, “The Unity of the Church Based on Personal Union with Christ,” in History, Essays, Orations and Other Documents of the Sixth General Conference of the Evangelical Alliance, ed. Philip Schaff and Irenaeus Prime (New York: Harper, 1874), sect. II, 139–44.

[9] Charles Hodge, Princeton Sermons (London: Thomas Nelson, 1879), 306–7.

[10] Charles Hodge, A Commentary on the Epistle to the Romans (New York: Robert Carter, 1880), 139.

[11] Charles Hodge, Systematic Theology, 3 vols. (1871; Grand Rapids: Eerdmans, 1982), 2.581, 3.104, 127, 227; idem, Commentary on the Epistle to the Ephesians (New York: Robert Carter, 1860), 289–354, esp., e.g., 289, 308, 315, 316.

[12] Hodge, Ephesians, 339–40.

[13] Cf. Robert Letham, The Westminster Assembly: Reading Its Theology in Historical Context (Phillipsburg, NJ: P & R, 2009), 235–36.

[14] See, e.g., John Owen, “Preface” to Patrick Gillespie, The Ark of the Covenant Opened; or a Treatise of the Covenant of Redemption Between God and Christ as the Foundation of the Covenant of Grace (London: 1677), n. p.; idem, The Works of John Owen, ed. William Goold, 24 vols. (Edinburgh and London: Johnstone and Hunter, 1850–53), 12.500–07; Francis Turretin, Institutes of Elenctic Theology, trans. George Musgrave Giger, ed. James T. Dennison, Jr. (Phillipsburg, NJ: P & R, 1992–97), XII.ii.5, 7, 13; Herman Witsius, Economy of the Covenants Between God and Man: Comprehending a Complete Body of Divinity, 2 vols., trans. William Crookshank (1822; Escondido, CA: The den Dulk Christian Foundation, 1990), II.ii.1–16; Samuel Rutherford, The Covenant of Life Opened, Or, A Treatise of the Covenant of Grace (1655; New Lenox: Puritan Publications, 2005), §§ 34–37 (pp. 413–74); Patrick Gillespie, The Ark of the Covenant Opened; or, A Treatise of the Covenant of Redemption Between God and Christ, as the Foundation to the Covenant of Grace (London: 1677). For an explicit confessional expressions of the pactum salutis, see Martin I. Klauber, “The Helvetic Formula Consensus (1675): An Introduction and Translation,” Trinity Journal 11 (1990), 103–23, canon. 4. Another instance exists in the Savoy Declaration of Faith and Order: The Confession of Faith of the Congregational-Independents (1658) (London: Evangelical Press, 1971), 8.1; cf. similar statements in the Canons of Dordt (1618–19), “The First Main Point of Doctrine Concerning Divine Predestination,” art. 7, in Jaroslav Pelikan and Valerie Hotchkiss, eds., Creeds and Confessions of Faith in the Christian Tradition, 3 vols. (Yale: Yale University Press, 2003), 2.572. Cf. Richard A. Muller, “Towards the Pactum Salutis: Locating the Origins of a Concept,” Mid-America Journal of Theology 18 (2007): 11–65.

[15] John Meyendorff, Byzantine Theology (New York: Fordham University Press, 1974), 160.

[16] Bernard McGinn and Moshe Idel, eds., Mystical Union in Judaism, Christianity, and Islam (Edinburgh: Continuum, 1996).

[17] F. B. Huey, Jr., and Bruce Corley, A Student’s Dictionary for Biblical and Theological Studies (Grand Rapids: Zondervan, 1983), 124, q. v. metaphor.

[18] Trevor Burke’s work, which is entitled, Adopted into God’s Family: Exploring a Pauline Metaphor, New Studies in Biblical Theology (Downers Grove, IL: IVP Academic, 2006).

[19] Kevin Vanhoozer, “Wrighting the Wrongs of the Reformation: The State of the Union with Christ in St. Paul and Protestant Soteriology,” in Jesus, Paul and the People of God: A Theological Dialogue with N. T. Wright, eds. Nicholas Perrin and Richard B. Hays (Downers Grove, IL: IVP, 2011), 254–55; Veli-Matti Kärkkäinen, “Response: Traditional Reformed View,” in Justification: Five Views, ed. James K. Beilby (Downers Grove, IL: IVP, 2011), 124; idem, One with God: Salvation as Deification and Justification (Collegeville, MN: Liturgical Press, 2004), 122; Wolfhart Pannenberg, Systematic Theology, vol. 3, trans. Geoffrey Bromiley (Grand Rapids, MI: Eerdmans, 1998), 213; N. T. Wright, Romans, NIB, vol. 10 (Nashville: Abingdon, 2004), 491; James D. G. Dunn, The Theology of Paul the Apostle (Grand Rapids, MI: Eerdmans, 1998), 231.

[20] Westminster Larger Catechism, qq. 70–71; Shorter Catechism, q. 33; cf. WCF XI.

[21] G. K. Chesterton, Orthodoxy: The Romance of Faith (1959; New York: Doubleday, 1990), 48.

John V. Fesko is a minister in the Orthodox Presbyterian Church serving as professor of systematic and historical theology and academic dean at Westminster Seminary California in Escondido, California. Ordained Servant Online, October 2012.

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