Promissio: The Reformational Turn in Luther’s Theology by Oswald Bayer. Translated by Jeffery G.Silcock(Minneapolis, MN: Fortress Press, 2025), xxxix +464 pp.

In 1971, when Promissio: Geschichte der reformatorischen Wende in Luthers Theologie by Oswald Bayer was published, its historical thesis ran against the grain of Luther research. Bayer’s doctoral supervisor, Ernst Bizer had (somewhat recently) proposed 1518 as the date of Luther’s “reformational turn.” As Theodor Dieter notes, however, this “late date” regards Luther’s theology before 1518 as “pre-reformational” and “most of his colleagues found this almost sacrilegious” (Lutheran Quarterly 39 2025: 256). By the mid-1980s, as Bayer records in the preface to the second German edition of Promissio, the situation had changed: Heiko Oberman referred to a late dating “boom” and Otto Hermann Pesch observed that “the ‘trend’ is now in favor of late dating” (xxvi). The bridge from the former to the latter scholarly context is, in large part, Promissio. Promissio is a book in two parts, bringing together Bayer’s inaugural dissertation and habilitation thesis. Part I explores Luther’s theology from 1514-1517; Part II defines, identifies, and traces the initial development of Luther’s “reformational turn.” The structure, method, and historical and theological theses are bound together. Bayer argues that Luther research always works with a “model of what is ‘actually reformational’” and “that such a presupposition must be declared up front.” For Bayer, the “textual context” in which a reformational model is paradigmatically expressed is The Babylonian Captivity of the Church, a treatise in which “we find the crystallization point of Luther’s reformational theology in the relationship between promissio and fides” (xxxvi). This provides Bayer with both a focus of research—the concept of promise—and a criterion for comparison: pre-reformational texts, even when moving towards, will finally fail to reflect, the promissio et fides relation of Babylonian Captivity, whereas reformational texts will correspond to this criteriological concept. From and with this Ansatz, Bayer offers close readings of Luther’s writing from 1514-18. It is within this methodological frame that Bayer proposes his basic historical thesis: “This concept of promise”—and therefore Luther’s reformational turn—“appears for the first time in the theses of circular disputation Pro veritate inquirenda et timoratis conscientiis consolandis … from the early summer of 1518” (183). Before considering Bayer’s theological interpretation of promise and faith, including both its difference from Luther’s early theology and its implications for Luther’s reformational theology, a note about Bayer’s method. This provides an opportunity to observe that this English translation appears some fifty-four years after the initial publication. The book both acknowledges this and includes material that makes it more than a translation of the original: the translator’s preface is a helpful orientation, as is Bayer’s preface to this English edition; there is a new retrospective afterward from Bayer that is both autobiographical and relates his programmatic research on promise to his many and significant publications from 1971 to 2025; Silcock not only translated Bayer’s German but also the numerous and often lengthy Latin and Early German quotations. Additionally, Bayer recognizes in the new preface that Promissio does not engage with the scholarly reception and critique of his historical and theological thesis, but he points to a companion article by Theodor Dieter that brings Promissio into dialogue with ongoing Luther research (cited above). Among Dieter’s many insightful observations is a comparison of distinct methods: while Bayer compares Luther texts over time, much research compares Luther to streams of late medieval theology and attends, for example, to his “growing criticism and rejection of scholastic theology, as expressed most strongly in the Disputation Against Scholastic Theology and the Heidelberg Disputation.” This contrast in approach can be combined with another alternative: “whether one considers ‘reformational’ the problem that Luther … identified and confronted e.g., Berndt Hamm, or rather,” with Bayer, does the reformational turn only occur once critique and question give way to theological “solution” (Dieter, Lutheran Quarterly 39 2025: 313 and 290). These differences account, in part, for diverse identifications and understandings of Luther’s theological development: earlier starting points remain possible because critique is present before 1518, Luther’s relationship to his theological inheritance—scholastic, mystical, and more—continues to be studied and many now emphasize aspects of Luther’s continuity with late medieval traditions, and it is now common to see the mounting criticism and insights of 1515-1520 as marked by movement and development rather than a decisive and datable turn. For Bayer, criticism of and departure from late medieval theology is not yet a reformational turn. Pointing to an often overlooked “series of retrospective self-testimonies … characterized by the keyword promise,” Bayer surfaces promissio as a possible criterion (xxvii), and according to his reading “The Babylonian Captivity of the Church (1520) claims that promissio (promise), and its counterpart fides (faith), is the canon of the sacrament and the epitome of the gospel” (xxxv). Compared with this criterion, the texts interpreted from 1514-1517 in Part I are identified as pre-reformational. Bayer offers numerous summaries of the structure of Luther’s early theology: “for the early Luther, faith is not created by an oral and binding word of salvation but only kept in motion by way of negation,” by a “word” that is one of “judgment that demands and brings about the humiliation of the hearer” (119, 392); “for the early Luther, the promise of salvation is realized specifically in the confession of sins and the judgment of the self” (129); “‘Faith,’ corresponding to the ‘word,’ is understood as the motion of penitence in total self-surrender, in the confession of sins and supplication, but not as in The Babylonian Captivity, as a creature of the audible and public promise—that is, the preached promise of the forgiveness of sins” (155; cf. the helpful summary on 393-98). The contrast expressed in those first and final quotations capture what Bayer understands as the decisive difference—the reformational turn. In Bayer’s own summary, Promissio has two principal purposes: “to demonstrate that Luther’s reformational theology, which stresses the word (promissio) that gives certainty of salvation, is found in The Babylonian Captivity” and “to demonstrate that the decisive turn in his theology only comes at the time of the indulgence controversy and that his distinctively reformation emphasis appears for the first time in his Pro veritate theses of 1518” (399). The indulgence controversy brought Luther both into sustained reflection on the sacrament of penance and study of Matthew 16:19 (as well as Matthew 18:18 and John 20:23). This, for Bayer, is the theological, exegetical, and pastoral context in which Luther discovers that “it is in the articulated word that God’s will is determined and the certainty of faith is grounded,” that “God not only reveals his will in the promise but also gives himself in it” (210), that “grace” is “bound to the promissio, understood as an external, oral, and public promise” (183). As Bayer traces this movement towards the “turn” of 1518, “the groundwork for the Pro veritate theses is laid in the Explanations of theses 7 and 38 of the Theses on Indulgences” (183). Explanation 7 “marks the beginning of the reformational turn” (192) because “certainty is found in the external word” rather than “in one’s inner experience” (187). The reason Bayer insists that even here “the reformational understanding of the word and faith … is not yet evident” is that the external word “presupposes” rather than “brings about” the reality it names: “the word is still not yet seen as a proper means of grace” (188-89, 192). With Explanation 38, however, “the seam” between the early and reformational Luther appears (202). As Luther now insists, “The declaration is too little,” suggesting that if the promise of absolution only announces what already is, “Christ’s binding word” becomes “‘irritum’—invalid, indeterminate, futile—and everything is made ‘uncertain’ for those absolved” (195). Explanation 38 thus identifies the limits of the descriptive and constative understanding of promise. Pro veritate discovers the creative and constitutive promissio. As theses 8 and 9 argue, “remission of guilt depends neither on the contrition of the sinner, nor on the office or authority of the priest,” but “rather it depends on faith, which means faith in the word of Christ” (207). Dieter describes this shift as a fundamental distinction between a conditional and general pactum to an unconditional and personal promise: the concrete and comforting word of forgiveness, before and apart from any basis other than the promise spoken pro me, both distributes salvation and grounds certainty (Lutheran Quarterly 39 2025: 273-75). The theological correlate of this historical thesis is a particular understanding of the relationship between promise and faith. The divine “word is opus operatum (the act done), a creative utterance that not only describes but establishes what is” (215). As Luther says of “the word, the word, the word,” the promise of the Gospel not only remembers and retells the story of Jesus; as both narratio and the promissio the gospel distributes, gives, offers, and bestows Jesus today and to you (see, e.g., 212-15; 222). Faith, then, which corresponds to the word as opus operatum, “cannot be opus operantis (the act of the doer)” because “faith subsists in the word” (215), “faith is … a creature of the oral word” (221). And because the word is not a generalized pactum but a concrete, particular, and personal promise, Bayer can speak of “the localization of the event of grace” and conclude that “certain faith is based on the specific word” (217-20). The implications of this promissio et fides relation, both historically and theologically, are significant. The binding of grace to the concrete, creaturely, and creative word of promise “overcomes” what Bayer calls “the Augustinian distinction between signum and res” (226). Because the Pro veritate theses end with reference to Romans 1:17 and also distinguish the word of judgment from the announced word of salvation, Bayer is able to link the autobiographical references to the promise to Luther’s more well-known reminiscences about the righteousness of God and the distinction between law and gospel (xxix-xxxi, 205-6). Chapters 6-10 of Part II consider the “reconfiguration” of Luther’s theology in light of “the reformational turn” (see 181). In relation to the Lord’s Supper, Luther came to see that the “gifting words” are the “chief part.” As Bayer puts it, in the Lord’s Supper “the sign and its significance coincide because the gift of salvation is exactly what the sign says, because the word gives and does what it promises” (273-75). Similarly, baptism is “constituted solely by God’s promise” (299), by “an assertoric, unconditional promise from God” that is a “performative word” (299-303). According to Bayer, this understanding of promise was discovered during the indulgence controversy in relation to Penance, then, over time, extended into reformational formulations of the other sacraments, and eventually “yielded a new understanding of preaching”: the promise that gives Jesus and performs death and resurrection in and with him—that is, the promises and present-tense gifts of Holy Communion and Baptism—is also the “basic text” and nature of proclamation (314-15). The hermeneutical and christological significance of this understanding of the promissio et fides relation can be seen in the “reconfiguration” of the pro me. Whereas the early Luther speaks of appropriation “for me” by meditation and conformity to an “archetypal” Christ, in the years after 1518 Luther reflects what Bayer terms a “trinitarian mediator Christology” (345) and understands that the gift of Christ is bestowed pro me by the promise (318-19, 335-37). The new retrospective afterward traces Bayer’s research up to and then after Promissio. As he says there, “the book is about the discovery of the word as a means of salvation” and—holding together the pastoral and scholarly that Luther’s Pro veritate theses combine—“reminds me Bayer that, as a pastor, I am called to bring God’s promise to people with a troubled conscience” (410-11). Fifty years after its initial publication, Promissio remains essential reading for all those studying Reformation history and theology. It continues to stimulate research, advance a substantial historical and significant theological thesis, provoke productive disagreement, invite close and contextual exegetical study, and finally articulate the gospel of “the deus pro nobis … in the oral promise of salvation” according to which “faith no longer bends back on itself … but is rather focused on its basis and support”: the concrete, creaturely, and creative promise that gives Jesus (343-45).