In a sermon "Columba Noæ" of February 1624 (1623 Old Style) to Convocation, he gave a list or personal panorama of leading theologians of the Church of England. In the same year he also refused the see of Gloucester: at the time English delegates to Dort were receiving preferment, since King James approved of the outcome. Hall was then involved as a mediator, taking an active part in the Arminian and Calvinist controversy in the English church, and trying to get other clergy to accept Dort. In 1627, he became Bishop of Exeter.