Societies cannot destroy the old system of faith while accepting a new religion. Human begins to transform the new belief system within the old belief system. One of the things they have to convert is the terminology of religion, which they accept. The change process of this new religious terminology can give concrete findings about the learning, adaptation, and transformation of a society to the new religion that it accepts. It takes a long time for the terminology of religion, which comes with the new religion, which is not entirely from its own language, to settle in the language of society, learning and the transformation takes place in certain stages. Determining the location of the language of the old texts in these stages will allow the dating of unspecified works and the identification of the author of the work. "Dede Korkut Stories" are important works of Turkish Language Literature. In this study, the religious terms in the Dresden and Vatican copies of "Dede Korkut Stories," which are thought to have been written after the 15th century, and the Turkistan/Turkmen Sahara copy found in 2019, were determined. I examined the determined religious linguistic terms comparatively in terms of their integration into the community language and also specify the stage at which the change and transformation of religious terminology took place.