The religious beliefs of George Rapp and the Harmony Society were a unique blend of orthodox Lutheran beliefs and emphases found within churchly and radical Pietism. Rapp’s mature theology (ca. 1830-1847) was characterized by two divergent trajectories—a biblical-eschatological and a mystical-spiritual trajectory. The biblical-eschatological trajectory was staunchly biblical and theologically conservative and included “core Reformation doctrine”, churchly Pietist emphases, and an “Anabaptist” ecclesiology. The desire for “deeper knowledge” and a numinous experience of God was reflected in the mystical-spiritual trajectory. It encompassed cabbalistic and theosophical descriptions of God and man, alchemistical practice and language, and an allegorical Scriptural hermeneutic. The author engages in a broad range of primary and secondary sources to show that Rapp’s theology and ministry were based in a wide reading of radical Pietist literature.