Students on introductory courses in secular religious studies and teacher training programs at Swedish universities often understand and conceptualize religion in an essentialist way. Whilst an essentialist understanding of religions is adequate in confessional training programs, it becomes an obstacle in secular higher secondary education and teacher training programs where an understanding of the variations within religions is required for higher grades. This article discusses four variants of essentialism observed in compulsory religious education, teaching materials and secular teacher training programs: 1) Essentialism in primary and secondary education shaped by the world religions paradigm. 2) Essentialism in religious education and teaching materials due to lack of source criticism towards religious narratives. 3) Essentialist views of religions expressed by (confessional) scholars, and 4) essentialism used in the construction of religious in- and outgroups. The article concludes that teachers involved in religious studies, regardless of level, need to be constant vigilant of expressions of essentialism in their own teaching as well as of essentialism in teaching materials. Although traditional, authoritarian and nationalist (TAN) ideology favors essentialist understandings of religions, these are not compatible with the cosmopolitan values expressed in the Education Act. Furthermore, essentialist education of religion based on the most devoted practitioners’ beliefs and practices creates a milieu where less devoted practitioners´ observance becomes questioned.