Karl Borromäus Adam attended the Philosophical and Theological Seminary at Regensburg and was ordained a priest in 1900. Adam then studied at the University of Munich and received his doctorate in 1904. In 1919 he became a professor at the University of Tübingen. He retired from that post in 1949. He is best known for his 1924 work, The Spirit of Catholicism. It has been widely translated, and is still influential in the work of 21st century theologians and spiritual seekers.

Karl Rahner was a German Jesuit and theologian who, alongside Henri de Lubac, Hans Urs von Balthasar, and Yves Congar, is considered one of the most influential Roman Catholic theologians of the 20th century.

Kassam Maaddi is a young Catholic from Taybeh, a graduate of the University Center for Journalism Education in Strasbourg, France and Birzeit University. He is a journalist and co-director of the CaritasJerusalem Youth Development Center.

Katherine Becker is an active member of the Dating Fast movement and a doctor of philosophy candidate at the University of Wisconsin–Milwaukee. She lives in Milwaukee, Wisconsin.

Kathy Coffey is a nationally renowned speaker and an award-winning writer. She is the author of several books including Experiencing God With Your Children and Hidden Women of the Gospels. She resides in Denver, Colorado.

Keith D. Lewis is a professor of religion at St. John’s Seminary, Camarillo. He is a frequent speaker at the Los Angeles Religion Education Congress and holds a Ph.D. from The Catholic University of America. He lives in Pasadena, California with his wife Kathryn.

Dr. Keith W. Frome, EdD, is the author of the award-winning What Not to Expect: A Meditation on the Spirituality of Parenting, and a regular contributor to WBFO, Buffalo's NPR affiliate radio station. He is a former elementary school headmaster and a curriculum developer. He lives in Buffalo, New York.

Keith Miller was a best-selling author of more than twenty books, and a well known speaker and consultant on renewal in the church. He lived in Austin, Texas with his wife Andrea.

Kenneth S. Leong is an accomplished Zen teacher, author, artist and poet who has a solid background in Christianity, Buddhism and Taoism. He has been engaged in interfaith dialogue since his teenage years as has given several talks in various churches, temples, universities and other spiritual and religious organizations. Mr. Leong publishes widely in the area of spirituality in the modern world. He holds a master’s degree from New York University. He lives in Rye, New York.