Argumentation is a rational method used in all areas of life, including education, to solve a problem, dispute or conflict. Our study is based on a discursive textual analysis of the use and possibilities of argumentation in religious education and our aim is to interpret the argumentation used in religious education through Habermas' model. For this purpose, we have analysed various texts selected from Islamic religion textbooks taught in Germany at primary, secondary and high school level. Our main finding is that Habermasian argumentation is successfully used in the textbooks in current events, whereas it is used in a "limited" and "conditional" way about historical interpretations. The main factor determining the boundary of argumentation is the requirements of the Islamic faith. The limit refers to the cessation of argumentation after a certain point. The condition, on the other hand, refers to the fact that a solution to the dispute can only be found by showing loyalty to a sacred source.