Öz
The substitution of reason for revelation and prophet in deism and secularism is a threat to the institution of revelation and prophethood of divine religions and hence Islam, a danger to discredit Muslim identity. This mission, loaded with reason, is also a challenge to divine religions and Islam. Accepting the mind as the only source in religious matters aims to purify religion from revelation and prophethood and to open up an unlimited and irresponsible space for people. This effort is to make human beings independent from the rules and rules of religion. It is to eliminate the declarations of revelation and to make the mind dominant in the religious field. It is to transform religion from being a divine religion into a human philosophy. The decrease in the intensity of religion in individual and social life and secularization, which expresses world-centered thinking and living, emerges as a natural result of having a deistic belief, on the other hand, of westernization or modernization. Secularization includes a sociological or psychological meaning, and with this concept, it is meant that religion loses its active role in people's social life or individual thoughts and feelings. In this case, deism in the field of belief and secularism in practical life stand out as two important factors that negatively affect the Muslim identity and threaten the Islamic lifestyle.