Secrecy is a central and integral component of all religious traditions. Not limited simply to religious groups that engage in clandestine activities such as hidden rites of initiation or terrorism, secrecy is inherent in the very fabric of religion itself. Its importance has perhaps never been more acutely relevant than in our own historical moment. In the wake of 9/11 and other acts of religious violence, we see the rise of invasive national security states that target religious minorities and pose profound challenges to the ideals of privacy and religious freedom, accompanied by the resistance by many communities to such efforts. As such, questions of secrecy, privacy, surveillance, and security are among the most central and contested issues of twenty-first century religious life. The Routledge Handbook of Religion and Secrecy is the definitive reference source for the key topics, problems, and debates in this crucial field and is the first collection of its kind. Comprising twenty-nine chapters by a team of international contributors, the Handbook is divided into five parts: Configurations of Religious Secrecy: Conceptual and Comparative Frameworks Secrecy as Religious Practice Secrecy and the Politics of the Present Secrecy and Social Resistance Secrecy, Terrorism, and Surveillance. This cutting-edge volume discusses secrecy in relation to major categories of religious experience and individual religious practices while also examining the transformations of secrecy in the modern period, including the rise of fraternal orders, the ongoing wars on terror, the rise of far-right white supremacist groups, increasing concerns over religious freedom and privacy, the role of the internet in the spread and surveillance of such groups, and the resistance to surveillance by many indigenous and diasporic communities. The Routledge Handbook of Religion and Secrecy is essential reading for students and researchers in religious studies, comparative religion, new religious movements, and religion and politics. It will be equally central to debates in the related disciplines of sociology, anthropology, political science, security studies and cultural studies.