Who among the Puritans advocated on behalf of a separation between church and state?
The Puritans, and in time the Founding Fathers of the United States of America, were heavily influenced in their thinking about the relationship between church and state by the prominent English jurist Edward Coke (1552-1634). Coke, who rose to become Chief Justice of the King's Bench, was a forceful advocate of establishing a firm separation between church and state. His consistent and articulate advocacy of such a separation earned him the enmity of English kings, but his philosophy proved enduring.
When the Puritans emigrated to what became known as New England in the early 17th Century, they brought Coke's influence with them. While very devout in their practice of religion, and while not believing that one could or should separate God from education or from the practice of civil government, many Puritan leaders were convinced of the imperative of avoiding the situation they had fled back in England. The relationship between the Crown and the Church in England was absolute. Edward Coke's struggles against that relationship and the Puritans' sense of disenfranchisement from the Church of England contibuted to their determination to establish a separation between church and state in their new home.
The most prominent Puritan leaders in the debate over the separation of church and state included Roger Williams, the founder of Rhode Island who had been excommunicated from the Puritans in England and whose lament about the "spiritual rape" of the people resulting from compulsory religious indoctrination was one of the more strident advocates for separation, and John Clark, founder of Newport.