Fr. Mark G. Boyer, a priest of the Diocese of Springfield-Cape Girardeau, Missouri, for thirty-nine years, is the author of forty books, including the two previous editions of "The Liturgical Environment", on biblical and liturgical spirituality. Besides serving as the director for the mission apostolate in his diocese, he has been part-time instructor in the Religious Studies Department of Missouri State University, Springfield, for twenty-eight years. He teaches courses in New Testament and Bible and Film. He gives workshops on the liturgical environment and assists in renovating churches.