Does Unity Matter? Luther on the Unity of the Church

by Eric J. DeMeuse

In his now classic study of Martin Luther, Heiko Oberman writes that ‘Luther does not stand for the alternatives “truth not unity,” “conscience not institution,” “individual not community”.’ This sentence sums up, I think, Oberman’s project rather succinctly; namely, to overturn an old, ingrained ‘Here I stand’ narrative of radical discontinuity between Luther and his late medieval forbears. Oberman’s approach to sixteenth century reform has born rich fruit and many progeny, though not without criticism. One implicit critique arises in John Maxfield’s 2010 study of Luther’s Genesis lectures (1535-1545)—the last of the Reformer’s prolific career.

The very title of Maxfield’s book, Luther’s Lectures on Genesis and the Formation of Evangelical Identity, suggests an attempt to reassert the narrative of Luther fashioning, in Maxfield’s words, a ‘new identity’ (p. 5). Maxfield’s book certainly has many strengths, educing from Luther’s Lectures central themes such as the hearing of the Word, the place of liberal learning, and Christian holiness, among others. Yet I was deeply troubled when he spoke of Luther’s ecclesiology. Maxfield points out that in exegeting the story of Cain and Abel, Augustine interprets the former as the ‘city of man’ and the latter as the Church, the ‘city of God’. Luther, however, interprets the division of brothers as a division of two churches—the false church and the true. Maxfield concludes that, ‘For Luther, the true church is not defined by catholicity or unity but by the word alone’ (p. 160), adding later that in Luther’s ‘radically new ecclesiology… Augustine’s concept of catholicity and unity as marks of the church cannot function and has no meaning’ (p. 178).

In what follows I will suggest a few ways in which Luther’s own words temper such a polarizing assertion, and perhaps even negate it altogether. The first comes in the very passage upon which Maxfield bases his assertion: Luther’s exegesis of the ‘two churches’, as it were, in Genesis. Maxfield renders the account accurately. However, for Luther, the line between the ‘false’ and ‘true’ church is far more porous than Maxfield’s analysis and conclusion suggest. Cain is given his sister for a wife, and Luther asserts, ‘I have no doubt whatever that because of his wife, who married her bloodthirsty brother in holy trust in God and out of obedience to her parents, God bestowed many personal blessings on Cain through all his descendants,’ referring in the same paragraph to these blessings as ‘fortuitous mercies (fortuitae misericordiae)’ (LW 1:313). There is no clear dividing line between the two churches in Luther’s exegesis, and thus Maxfield’s conclusion appears a significant leap from the premises offered in the text. In fact, Luther sounds much more like Augustine—who frequently speaks of the Church as a corpus permixtum, or mixed body (see his Homilies on First John)—than Maxfield is willing to warrant.

Second, throughout his career, Luther would occasionally list ‘the marks of the Church,’ with the lists varying slightly in length and content. His most famous enumeration appears in his On the Councils and the Church from 1539 (LW 41). Here he lists seven marks: the holy Word of God, the sacrament of baptism, the Eucharist, the office of the keys exercised publicly, consecrated ministers, prayer, and the holy cross. These marks speak to a unity rooted not only in the Scriptures, but also in sacramental and apostolic realities extending visibly through time. An example from his On Rebaptism (1528) will further illustrate this. There, Luther defends the practice of infant baptism against the Anabaptists by arguing from the universality and continuity of the Church: if infant baptism were invalid, then the Church would have ceased to exist for a period of time, and thus ‘the article of faith—I believe in one, holy, Christian Church—would be false (Ich glaube eine heilige Christliche kirche)’ (WA 26:168). Unity is thus a central piece of Luther’s polemic against ‘the enthusiasts’ (Schwärmer), as he sees them.

Third and finally, Luther offers a similar argument in 1542 during a promotiondisputation for John Maccabaus Scotus. Therein, Scotus claims that the Church did not exist under the papacy (nulla fuit Ecclesia). At this Luther interjects that the Church ‘always existed, even if it was not visible’ (Semper fuit Ecclesia, etiamsi non visibilis). He immediately tempers the latter half of this response, however, by adding that the church was indeed visible to a degree. Even in the church of the papists (ecclesia papistarum) certain ‘external marks’ (notae externae) were preserved ‘by a divine miracle,’ including the Scriptures, baptism, the sacrament of the altar, and ‘many good monks, such as Bernard [of Clairveaux] and Bonaventure, who were saved’ (WA 39/2:167-8). Here Luther exhibits a concern to defend the continuity and unity of the church—a unity grounded in the Scriptures, the sacraments, and the witness of holy men and women. Thus whereas Maxfield argues that for Luther the true church is marked by the word and affliction (see p. 160) instead of unity, Luther argues that the church is marked by such realities along with the continuous, historical, and visible witness of her sacraments and saints. And it is further noteworthy that Luther defends this latter aspect while forming the next generation of Lutheran divines.

These are just a few texts wherein Luther emphasizes the visible continuity, catholicity, and unity of the Church. They indicate that Luther’s ecclesiology does not fit neatly into Maxfield’s strict dichotomy. I do not suggest, however, that Luther’s understanding of unity neatly meshes with that of either Catholics or Lutherans (or other denominations) today. Rather, I only suggest that catholicity and unity play a significant role in the Reformer’s ecclesiology—a facet oft neglected, but one of vital importance for ecumenical dialogue, and one much in need of further study.


  1. Heiko Oberman, Luther: Man Between God and the Devil, 250.

One thought on “Does Unity Matter? Luther on the Unity of the Church

  1. For more on the theme of “fortuita misericordia” in Luther’s Genesis lectures, see Mickey L. Mattox, “Fortuita Misericordia: Martin Luther on the Salvation of Some Biblical Outsiders,” Pro Ecclesia 17 (2008): 423-441.

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