Historians of English Puritanism concede that by the 1650s the revolution of the saints had run its course. The political activism of the Presbyterians, Independents, and radical sects during the war gave way in the Interregnum period to more private concerns of personal and collective piety. The pattern of changing popular mood in an unstable political environment is clear enough, but the social meanings of religion as devotional practice are more obscure. Lost in the historical analysis is the realization that piety is an expressive form of communication in the politics of social life. In times of militant controversy the public role of piety is more obviously ideological, and devotional literature achieves publicity in the sense of promoting sectarian reformation. From this perspective, I shall focus on Henry Jessey's The Exceeding Riches of Grace Advanced (London, 1647) and will place it in the context of the art of dying (ars moriendi) tradition and of factional pluralism in civil war London. The story of Sarah Wight's illness and conversion experience attempted to unify religious and political divisions in a crucial revolutionary year. Within a traditional framework of devotional literature, Jessey communicated a political message. Sarah Wight herself was not a passive recipient of ministerial advice, but an influential teacher of radical theology. In fact, it was the customary form of the artes moriendi tradition that allowed her conversion to become an occasion for lay preaching.