Irenaeus' theology of the Holy Spirit is often highly regarded amongst theologians today, but that regard is not universal, nor has an adequate volume of literature supported it. This study provides a detailed examination of certain principal, often distinctive, aspects of Irenaeus' pneumatology. In contrast to those who have suggested Irenaeus held a weak conception of the person and work of the Holy Spirit, Anthony Briggman demonstrates that Irenaeus combined Second Temple Jewish traditions of the spirit with New Testament theology to produce the most complex Jewish-Christian pneumatology of the early church. In so doing, Irenaeus moved beyond his contemporaries by being the first author, following the New Testament writings, to construct a theological account in which binitarian logic did not diminish either the identity or activity of the Holy Spirit. That is to say, he was the first to support his Trinitarian convictions by means of Trinitarian logic. Briggman advances the narrative that locates early Christian pneumatologies in the context of Jewish traditions regarding the spirit. In particular, he argues that the appropriation and repudiation of Second Temple Jewish forms of thought explain three moments in the development of Christian theology. First, the existence of a rudimentary pneumatology correlating to the earliest stage of Trinitarian theology in which a Trinitarian confession is accompanied by binitarian orientation/logic, such as in the thought of Justin Martyr. Second, the development of a sophisticated pneumatology correlating to a mature second century Trinitarian theology in which a Trinitarian confession is accompanied by Trinitarian logic. This second moment is visible in Irenaeus' thought, which eschewed Jewish traditions that often hindered theological accounts of his near contemporaries, such as Justin, while adopting and adapting Jewish traditions that enabled him to strengthen and clarify his own understanding of the Holy Spirit. Third, the return to a rudimentary account of the Spirit at the turn of the third century when theologians such as Tertullian, Origen, and Novatian repudiated Jewish traditions integral to Irenaeus' account of the Holy Spirit.

For too long certain scholars have been content to portray Irenaeus of Lyons as a well-meaning churchman but incompetent theologian. By offering a careful reading of Irenaeus' polemical and constructive arguments, God and Christ in Irenaeus contradicts these claims by showing that he was highly educated, trained in the rhetorical arts, aware of general philosophical positions, and able to use both rhetorical and philosophical theories and methods in his argumentation. Moreover, the theological account laid down by his pen was original and sophisticated, supremely so for one of the second century. In contrast to readings that minimize the metaphysical dimension of Irenaeus' theology, Anthony Briggman establishes as pillars of Irenaeus' polemical argumentation and constructive theology his conception of the divine being as infinite and simple, the reciprocal immanence of the Word-Son and God the Father, divine generation, the union of the divine Word-Son and human nature in the person of Christ, and the revelatory activity of the infinite and incomprehensible Word-Son, amongst other features of his theology. Briggman offers a fundamentally new understanding of Irenaeus and his thought.

Guilds and conferences have grown up around historical theology, yet no volume has ever been dedicated to the definition and illustration of the method undergirding historical theology. This volume both defines and illustrates the methodology of historical theology, especially as it relates to the study of early Christianity, and situates historical theology among other methodological approaches to early Christianity, including confessional apologetics, constructive theology, and socio-cultural history. Historical theology as a discipline stands in contrast to these other approaches to the study of early Christianity. In contrast to systematic or constructive approaches, it remains essentially historical, with a desire to elucidate the past rather than speak to the present. In contrast to socio-historical approaches, it remains essentially theological, with a concern to value and understand the full complexity of the abstract thought world that stands behind the textual tradition of early Christian theology. Moreover, historical theology is characterized by the methodological presupposition that, unless good reason exists to think otherwise, the theological accounts of the ancient church articulate the genuine beliefs of their authors. The significance of this volume lies in the methodological definition it offers. The strength of this volume lies in the fact that its definition of the historical method of studying theology is not the work of a single mind but that of over twenty respected scholars, many of whom are leaders in the field. The volume begins with an introductory essay that orients readers to various approaches to early Christian literature, it moves to two technical essays that define the historical method of studying early Christian theology, and then it illustrates the practice of this method with more than twenty essays that cover a period stretching from the first century to the dawn of the seventh.