The belief of John Winthrop that would be changed when the U.S. government was set up was that C) The Church and State should be joined together in leading the people.
When the colonists founded the U.S. government, they opted to separate religion from the state to avoid the problems of governance that they witnessed in Europe.
In conclusion, option C is correct.
Find out more on John Winthrop at https://brainly.com/question/850335.