Professor Stewart has been a Benedictine monk of Saint John’s Abbey since 1981. He publishes regularly in his field of eastern and western Christian monastic history. Most recently he has been a member in the School of Historical Studies at the Institute for Advanced Study, Princeton, NY, a Guggenheim Fellow, and a Resident Scholar at the Collegeville Institute. He is currently writing a new study of the origins of Christian monasticism. Because of his work at the Hill Museum & Manuscript Library leading the digitization and cataloging of more than 200,000 endangered Christian and Islamic manuscripts in libraries around the world, he has been featured in international radio programs, newspapers and documentaries, and the CBS News television program "60 Minutes.

Professor Stewart is the 2019-2020 Frank M. Updike Memorial Scholar.

Professor Stewart was named the 2019 Jefferson Lecturer by the National Endowment for the Humanities, the highest honor the federal government bestows for distinguished intellectual achievement in the humanities.