Roland Allen was one of the most influential mission thinkers of the twentieth century. As a High Church Anglican, he had great respect and value for Church tradition, but was quick to confront cultural preferences when they appeared to contradict biblical prescriptions. The Ministry of Expansion: The Priesthood of the Laity reflects his thoughts that dealt with Communion-related activities in the Majority World where the Anglican Church did not have well-developed church structures and priests. In this work, Allen argues that there are times and circumstances when non-clergy must take the lead in the administration of Holy Communion. Written around 1938, The Ministry of Expansion: The Priesthood of the Laity has remained unpublished until now. The work you hold represents one of the last book-length manuscripts written by Allen and includes a collection of articles by contemporary Allen scholars. Though nearly eighty years since he first put pen to paper, Allen's principles and convictions still speak to the Church with great gravitas. What should be the response when the Church's cultural preferences are unable to keep up with the work of the Spirit on the mission field? This was a not only a question in Allen's day, but one for every generation of believers.