The Karbis, an indigenous group primarily inhabiting Assam and nearby regions, have long preserved distinct cultural and religious traditions rooted in animism and nature worship. However, the introduction of Christianity, spearheaded by missionaries during the colonial and post-colonial periods, brought profound changes to their socioreligious landscape. This study examines the Karbi tribe of Northeast India, focusing on their ethnicity, cultural practices, and the transformative impact of Christian missionary efforts on their society. The research explores the methods employed by missionaries to facilitate conversion, including education, health care, and community engagement, while also considering the voluntary and involuntary dimensions of the Karbis’ transition to Christianity. Particular emphasis is placed on the role of missionary-led institutions in redefining Karbi identity and fostering social mobility. Additionally, the study interrogates the interplay between tradition and modernity, addressing how the Karbi community has negotiated cultural preservation amidst religious transformation. Through a combination of historical analysis and ethnographic fieldwork, this paper provides nuanced insights into the complexities of religious conversion, the resilience of ethnic identity, and the evolving dynamics between indigenous communities and external influences. The findings reveal a dual narrative of empowerment and cultural displacement, reflecting broader themes of globalization, colonial legacies, and the ongoing redefinition of indigenous identities in contemporary India.