Johann Arndt (1555-1621) was an influential figure in early modern piety and pietism in Germany. This volume focuses on Arndt's broadly neglected prayer book "Garden of Paradise" (Paradiesgärtlein). Park studies Arndt and his position in Lutheranism is his reception of medieval-mystical and extra-Reformation sources, whose thoughts Arndt allowed to flow into the Protestantism of the 17th Century. Influences on the "True Christianity" (Wahres Christentum, 1605-1610) are Johann Tauler, Theologia Germanica, Angela of Foligno, The Imitation of Christ, Valentin Weigel and Paracelsus and above all the materials of the (pseudo-) Bernard of Clairvaux on the "Garden of Paradise" (Paradiesgärtlein, 1612).