This article examines the changes in religious beliefs among young Muslims in Islamic countries. These changes are generally attributed to the progress of science and technology. This article aims to show that although religious beliefs in Islamic countries are changing at a much slower pace than in Western countries, these changes cannot be explained by the classical theory of secularization. According to this theory, there is a positive and direct correlation between the progress of science and the decline in religiosity. Based on the findings of the World Value Project (WVS), the decline in religiosity in Muslim countries is occurring at a slower pace than in developed countries. This article points to some of the reasons for the resistance of Muslims to secularization. The Islamic tradition has gone through a period called the "Islamic Golden Age", which has been an excellent example of the harmony of science and religion. Relying on such historical experience has always encouraged Muslims to believe in the possibility of reconciling science and religion. In addition, the content of the Quran is full of references to nature and encouragement to study it. Also, Islamic jurisprudence, especially in some of its sects, shows good flexibility with scientific findings (such as Evolution) and developments in the modern world (such as the right to determine gender). However, the article emphasizes that this does not mean that there is no religious change in Muslims, especially among younger generation. Religious states and their interference in the current affairs of the people and the restriction of some individual freedoms, along with economic difficulties in some of these countries, are the causes of abandoning religion or changes in the type of religiosity. Referring to some statistics, this article shows the factors involved in explaining the changes in religiosity in Muslim majority countries is more complex than classical view of secularization can explain.