Katupela guguya, or "exchange of sermons," is a current practice in the Trobriand Islands in which whole villages visit close or distant communities to give prayers on a set date. The Word of God is gifted by visiting parties who preach for their hosts; hosts will later reciprocate, offering other Bible passages when they visit their current guests' village. Modeled partly on the familiar patterns of circulation of the Kula exchange, katupela guguya also entails more material exchanges, including, on some occasions, Kula valuables. The reification of Christian cultural elements not only facilitates their circulation in exchange circuits; it also helps define these circuits, investing them with new meanings. This increased mobility (of things and ideas) has been capitalized on by some individuals to posit a coherent continuity between traditional magic practices and present-day understandings of Christianity. The exchange of sermons offers original insights on how people conceptualize and negotiate social change in the Massim cultural region (Milne Bay Province, Papua New Guinea) to which the Trobriand Islands belong.