The present book argues that Martin Luther and his first allies and intra-Reformation critics (Andreas Bodenstein von Karlstadt and Thomas Müntzer) appealed to suffering to teach Christians to distinguish between true and false doctrine, teachers, and experiences. In so doing, they developed and deployed categories of false suffering, in which suffering was received or simply feigned in ways that hardened rather than demolished self-assertion. These ideas were nourished by the reception of teachings about annihilation of the self and union with God received from post-Eckhartian mysticism. Luther, Karlstadt, and Müntzer developed this mystical inheritance in different directions, each of which intended to shape Christians for differing forms of ecclesial-political dissent: Luther redefined union with God as a union with Christ through faith and the Word, and he counseled Christians to endure persecution as divine work under contraries; Karlstadt described union with God as “sinking into the divine will,” and he upheld this union as a postmortem goal that required, here and now, constant self-accusation and improvement on the part of the individual and the community; Müntzer looked for God to possess souls according to the created order, making Christians into actors for the execution of God’s will on the earthly plane. The democratization of mysticism that so many scholars have attributed to these reformers’ teachings involved a delimitation: mysticism joined to Reformation teaching was used to identify false experiences, false teachers, and ultimately false Christianity.