Roger Williams was one of the original founders colonial Rhode Island. He was a religious dissenter banished from the Puritan society in Massachusetts. He dictated that people should not be persecuted for practicing their own religious beliefs, and that an individual's conscience is beyond the control of any civil or church authority.
Minister Roger Williams
The other major founder of colonial Rhode Island was Anne Hutchinson. Her banishment from Puritan society resulted from her role in the Antinomian movement. Hutchinson's primary belief, antinomianism, stated that faith alone is necessary to reach salvation in heaven. Like Williams, she advocated separatism.
Anne Hutchinson
Likewise, colonial Rhode Island was established as a society with religious freedom and the separation of Church and State. Baptism, Judaism, Catholicism, and the Quaker's faith as well as other religious minorities thrived in this colony.