Throughout history, we see that various communities have turned to music as an art form to express emotions, which are the most powerful aspects of our being. Another notable aspect is the use of music as a form of religious expression. In the religious traditions of Judaism, Christianity, and various groups (Syriac, Greek, Armenian, Presbyterian), musical practices are prominent, while in Islam and specifically in Turkey, examples such as the call to prayer recited five times a day, the melodic recitation of praises during the Hajj and Umrah rituals, and the Mevlevi Sema ceremonies represent intertwined forms of music and religion in daily life. According to Tolstoy, "Art is not pleasure, nor consolation, nor entertainment; art is a noble task. Art is the organ that transmits conscious knowledge to emotions in human life." The effects of religious music on human psychology, both as a carrier of collective religious values and as a means of providing religious experience, are intriguing. Therefore, exploring religious music as the subject of a long-term music therapy study, based on the intertwined relationship between religion and psychology, is one of the unique features of this work. This study thoroughly addresses the historical development of music therapy in both Europe and Turkey, the approaches and models used in music therapy, music therapy methods, and principles of practice. The effects and areas of use of music therapy are examined in light of current research findings in the literature. Additionally, this work offers extensive information on music therapy, and includes recent studies on the relationship between music therapy and religion, as well as religious music therapy in both the world and Turkey, which is another distinctive feature of this research.