In 1720, Johnson became Congregationalist minister of a church in West Haven, Connecticut. Even though "he had much better offers", he took up the position for the sake "of being near the college and library". There he, Yale Rector Timothy Cutler, Yale Tutor Daniel Brown, and six other Connecticut ministers, including the Rev. Jared Eliot of Clinton, and Johnson's friend the Rev. James Wetmore of North Haven, formed a group to study the Anglican divines and the "doctrines and facts of the primitive church". Their reading and discussions led them to question the validity of their ordinations, and the book group members converted from embracing a Presbyterian polity on ordination to an Episcopal one sometime in 1722. At Yale's September 13, 1722 commencement, in a very public and dramatic event labeled the “Great Apostasy” by American religion historian Sidney Ahlstrom, the nine member group declared for the episcopacy. After strong pressure from the Governor and their family and friends, five of the nine recanted, but Johnson, Cutler, Brown and Wetmore, refused to change their decision, and were expelled from their positions at Yale and their Congregational ministries.