John Calvin, the Frenchman who became one of the most famous Christian theologians and controversial figures in history, initially wanted nothing more from life than to study and write in ivory tower academia in the 16th century. Intrigued by the nascent Reformation, he first fled Paris to avoid punishment for heresy, and then was shamed by reformed French evangelist William Farel into serving in the church in Geneva, Switzerland, a city of corruption in a land of libertines.
Most religions are sacral, meaning that they are tied to a certain ethnic group and geographic location. To be a Sumerian was to live in Mesopotamia, follow Sumerian culture and worship Sumerian deities such as Anu, Enki and Inanna. To be an Egyptian was to live along the Nile, speak Egyptian and worship Orisis, Isis and Anubis. To be a Hebrew was to live in Palestine, follow the Law of Moses and serve Jehovah. The early Christian church broke this mold, with believers in every people group, and every location in much of the world. The civic religion was emperor worship, intended to unify to the Empire against threats within and without, and the main cause of Christian persecution was that believers did not join the civic religion. Thus they were guilty of treason.