Religious libraries have evolved through time and space and their contributions to the present day libraries have not been given a thorough coverage in the corpus of librarianship. While the aforementioned libraries have taken various forms throughout their histories in supporting their broader institutions' missions and have had various kinds of relationships with other types of libraries, their contributions deserve great attention in order to unearth the roots of present day librarianship. This chapter explores the development of religious libraries and how they remain a force to reckon with in the the history of librarianship. Using literature review, the chapter explores the evolution of religious libraries in the context of religion and how such institutions can contribute towards global peace.