In this historical study, Jonathon D. Beeke considers the various sixteenth- and seventeenth-century Reformed expressions regarding the duplex regnum Christi (the twofold kingdom of Christ), or, as especially denominated in the Lutheran context, the "doctrine of the two kingdoms." While a sampling of patristic and medieval sources is considered, the focus is on select magisterial Reformers of the sixteenth century and representative intellectual centers of the seventeenth century (Leiden, Geneva, and Edinburgh). A primary concern is to examine the development of these formulations over the two centuries in question, and relate its maturation to the theological and political context of the early modern period. Various conclusions are offered that address the contemporary "two-kingdoms" debate within the Reformed tradition.

This research guide introduces scholars to the field of Reformed theology, focusing on works of the twentieth and twenty-first centuries in the English language. After a brief introductory section on the debates about what counts as "Reformed theology," Martha Moore-Keish explores twenty-one major theological themes, with attention to classical as well as current works. The author demonstrates that this stream of Protestantism is both internally diverse and ecumenically interwoven with other Christian families, not just a single clearly defined group set apart from others. In addition, this guide shows that contemporary Reformed theology has been rethinking the doctrines of God, humanity, and their relationship in significant ways that challenge old stereotypes and offer fresh wisdom for our world today.

Calvinism in the Polish-Lithuanian Commonwealth 1548-1648 offers an in-depth history of the Reformed Churches in the Polish-Lithuanian Commonwealth in their first hundred years. Kazimierz Bem analyses church polity, liturgy, the practices of Calvinist church discipline and piety, and the reasons for conversion to and from Calvinism in all strata of the society. Drawing on extensive research in primary sources, Bem challenges the dominant narrative of Protestant decline after 1570 and argues for a continued flourishing of Calvinism in the Commonwealth until the 1630s.