Philipp Jakob Spener was the founder of the Lutheran pietistic movement; his letters are an essential source for research into the Early Modern Age, not only in terms of church history, but also regarding cultural history and the history of ideas.
The edited 'Letters from the Berlin period 1691-1705' shed light on Spener's period as provost at the Church St. Nikolai in Berlin. Letters from the same period are published in 'Briefwechsel mit Adam Rechenberg' from volume 3 and in 'Briefwechsel mit August Hermann Francke'.
Volume 2 contains 212 letters from the years 1694-1696 and reflect a first high point in his disputes with the opponents of Pietism. They provide insights into the origin and reception of his polemics. Among other things, they deal with the dispute over chiliasm and the accusation that Spener disregarded the Lutheran confessional writings. Numerous letters illustrate his influence on personnel developments in the theological faculties in Halle and Giessen as well as on the filling of important clerical positions in Brandenburg.