Final answer:
Roger Williams was banished by the Puritan leaders of the Massachusetts Bay Colony due to his progressive beliefs advocating for religious freedom and his critique of Puritan policies, leading him to establish Rhode Island as a haven for religious tolerance.
Step-by-step explanation:
The Puritan leaders of the Massachusetts Bay Colony responded to Roger Williams' actions by banishing him. Williams' controversial beliefs, including his advocacy for religious toleration and his opposition to the confiscation of Native American land without compensation, conflicted deeply with Puritan ideology. He challenged the Puritan's theocratic society by arguing for a separation of church and state, and for the idea that the state should not punish individuals for their beliefs, which the Puritan authorities saw as dangerous.
Williams' conviction for spreading 'dangerous ideas' and his subsequent banishment in the early 1630s underscore the strict religious orthodoxy that the Puritan leaders aimed to maintain. Despite Williams' ousting, he continued to uphold his ideals and eventually founded the colony of Rhode Island, which became a refuge for those seeking freedom of conscience and was characterized by greater religious tolerance than the Massachusetts Bay Colony.