Roger Williams (l. 1603-1683 CE) was a Puritan separatist who believed in and advocated for the separation of church and state, claiming that politics corrupted religion. He advocated for this policy in a number of his written works but, most succinctly, in his 1655 CE A Letter to the Town of Providence in which he compares a commonwealth or community to a ship on which many people of differing beliefs and lifestyles sail toward a common destination. As the captain of the ship may discipline the passengers and crew in the interests of order and common safety but not in matters of religion, so too a magistrate only had authority over civil, not religious, matters.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/1662/roger-williams-a-letter-to-the-town-of-providence/.