This PhD project examines how two modern religious movements, the Ramakrishna Movement within Hinduism and the Nur Movement in Islam, engage with the question of religious diversity. Modernity emerged with a Western focus and has gradually evolved into a global transformation process that has had a profound effect on different religious traditions and cultural structures. This has intensified interfaith encounters, establishing religious diversity as one of the defining fact of the modern world. However, reactions to this fact are not homogeneous within religious traditions. However, reactions to this phenomenon have not been homogeneous within religious traditions. While some movements have sought to adapt by developing reformist approaches to the challenges of modernity, others have adopted a more conservative and exclusionary stance, displaying an attitude that rejects the 'other'. However, revivalist approaches that maintain ties with tradition while attempting to interpret religious diversity positively have also emerged in the modern era. Notable examples of this approach include the Ramakrishna Movement in the Hindu world and the Nur Movement in the Islamic world. Notable examples of this approach include the Ramakrishna Movement in the Hindu world and the Nur Movement in the Islamic world. Both movements have responded to the religious diveristy by developing unique theological and discursive frameworks. The Ramakrishna Movement developed an approach centred on the idea of 'harmony of religions', whereas the Nur Movement reinterpreted interfaith relations through the concept of 'alliance'. This study aims to analyse the frameworks, arguments, methods and strategies developed by these two movements in the context of religious diversity, and their theological positions within the exclusivism, inclusivism and pluralism debates.