In recent decades, marked by the rise of comparative religious studies, the need for a theological system that encompasses not just one religion but all major world religions has been widely discussed. Wilfred Cantwell Smith is one of the leading proponents of this view. He defines global theology as "the theology of the religious history ofhumankind."Global theology is a comparative theology of religion that is constructed collectively and is, therefore,"acceptable and even convincing to all of humanity." Using this theological framework, Smith envisions a “global process of religious convergence.” He emphasizes that global theology is "a theology for which 'religions' are the subject, not the object; a theology that emerges from 'all the world’s religions,' from all religious communities and sub-communities of humanity." In other words, global theology is “the theology of the religious history of humankind” or “the history of our human faith.” While Smith considers such a theological system possible based on the unity of religious history, faith—as the essence and common principle of religions—and the potential for a new kind of knowledge beyond 
scientific objectivism and sectarian subjectivism, some scholars argue that the realization of such a theology is impossible due to the lack of convergence among many of the philosophical presuppositions of different religions, especially between Abrahamic and non-Abrahamic traditions.