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 correspondence between Spener (1635-1705) and Adam Rechenberg (1642-1721) makes up the most extensive part of the preserved letters, which up to now were only available as original manuscripts. The rich corpus offers comprehensive insights into Spener's life, thinking, work, and networks that portray many areas of contemporary spiritual and societal life outside of religious circles.The third volume includes 179 letters from the years 1691-1693. The correspondence provides detailed insights into Spener's new position as provost of St. Nicolai and counsellor of the Brandenburgian Consistory in Berlin, into the political, ecclesiastical and theological processes of the time as well as into the intensive debates surrounding Pietism.