This essay attempts to address some of the central differences and similarities in the debate between Gavin D’Costa (Catholic) and John Hick (Protestant) about the nature and legitimacy of modern religious pluralism in the light of their own real-life religious, philosophical, social, and cultural differences. Given that it is a debate at advanced academic levels between two top scholars in religious studies which assumes a great deal of prior academic knowledge, our understanding of the key features of this controversy must first be well-situated within an extended discussion of clearly defined operational terms such as pluralism, religious pluralism, relativism, inclusivism, syncretism, and ecumenism. The essay then provides a brief review of the historical origins of the debate, followed by an outline of the general Catholic and Protestant views on religious pluralism which infuse the debate. This essential background information is followed by an assessment of some of the main weaknesses and strengths of each point of view although critical commentaries are also offered where appropriate throughout the essay. The concluding remarks suggest that the D’ Costa position appears to contain greater legitimacy and validity from a strict biblical point of view, although it is not without its own weaknesses.