This book examines how socio-political surroundings have affected the evolution of Yarsani religious thought and why the Yarsani religious belief, despite its fundamental disagreement with Islamic tenets, has been affiliated with Islam. It also considers the historical context and socio-religious milieu in which the Yarsani belief appropriates religious forces to survive, how Yarsanis experience their religion in Islamic society, and what differences are significant in their lived experiences. The author explores how the experience of worship influences real life for the Yarsanis from the perspectives of sociology, behaviorism, content analysis, cultural studies and ethnography in Iran and diaspora with focus on Sweden. Yarsani followers became known as those who “don’t tell secrets,” primarily because they were not allowed to promote and advertise their religion in public, but recently have started to reveal their religion, especially in social media. This book discovers thetransformation of this religion, and in particular in which context an individual can change the content of religion, and bring about new ideas regarding religion and belief.