Mysticism is a religious phenomenon open to different interpretations, and it receives varying expectations from its followers, which corresponds to the nature of the religion. All religions act with the schools of thought and doctrines within the same religion. In his book Sufismus und Theologie - Grenze und Grenzüberschreitung in der islamischen Glaubensdeutung, Reza Hajatpour addresses the most important aspects of mystical theology. The investigation is primarily intended to analyze the approaches of teachings and understandings from the offer of Sufi beliefs and the associated controversy, which compared to the apologetic and dogmatic interpretation of the beliefs and also characterizes the limit and transgression of an Islamic-mystical theology.