Answer:
He wanted the freedom to engage in religious practices different from theirs.
Step-by-step explanation:
Roger Williams, founder of Rhode Island, rebeled against the Massachisetts Bay colonists because he firmly believed that people should have the freedom to believe in whatever they wanted to believe in, and that church and state should be separated, when he was banned from Massachusetts Bay he along with others founded Rhode Island, a place for religious minorities and soul liberty that had no official religion and had church and state separated.