Henri Jozef Machiel Nouwen (Nouen), (Nijkerk, January 24, 1932 – Hilversum, September 21, 1996) was a Dutch-born Catholic priest and writer who authored 40 books about spirituality.

Nouwen's books are still being read today. His books include The Wounded Healer, In the Name of Jesus, Clowning in Rome, The Life of the Beloved and The Way of the Heart. After nearly two decades of teaching at the Menninger Foundation Clinic in Topeka, Kansas, and at the University of Notre Dame, Yale University and Harvard University, he went to work with mentally challenged people at the L'Arche community of Daybreak in Toronto, Canada.

While visiting the community, he saw a photograph of Rembrandt's "The return of the prodigal son", that caused him a deep impression. He decided to see the paintig personally and traveled to San Petersburg (Leningrad at those times) to visit the Hermitage Museum where it is kept. This resulted in a several day contemplation of the painting, and the book of the same name, probably his most famous.

Sue Mosteller, C.S.J. (born 1933) is a writer who lives in Toronto, Canada.

Sue Mosteller is a Sister of St. Joseph of Morrow Park in Toronto. Since 1971, Sr. Mosteller has also been a member of the L'Arche Daybreak Community which is part of an international network of faith-based communities for those with developmental difficulties. In 1976 Mosteller became L'Arche Daybreak’s second Community Leader (Executive Director), and a few years after that, Sue was named the first International Coordinator for L’Arche after Jean Vanier, the founder of L'Arche.

In November 2011, Mosteller received an Honourary Doctorate from Tyndale University College and Seminary in Toronto.

She was a colleague and close friend of Henri Nouwen when he lived at L'Arche Daybreak (1986 - 1996). When Henri Nouwen died in 1996, he entrusted Sue Mosteller with his estate, making her the literary executrix of his works. She serves on the board of the Henri Nouwen Society. She continues to be a member of the L'Arche Community. which is an international network of faith-based communities for those with developmental difficulties. Additionally, Mosteller lectures and gives retreats around the world and currently lives in Toronto, Canada.

Frederick Antony Ravi Kumar Zacharias (born 1946) is an Indian-born, Canadian-American evangelical Christian apologist. Zacharias is the author of numerous Christian books, including Gold Medallion Book Award winner Can Man Live Without God? and bestsellers Light in the Shadow of Jihad and The Grand Weaver. He is the founder and chairman of the board of Ravi Zacharias International Ministries, host of the radio programs Let My People Think and Just Thinking, and visiting professor at Wycliffe Hall of Oxford, where he teaches apologetics and evangelism. Zacharias studied as a visiting scholar at Cambridge University and held the chair in Evangelism and Contemporary Thought at Alliance Theological Seminary from 1981 to 1984. Commentator Chuck Colson referred to Zacharias as "the great apologist of our time."

Zacharias was born in Madras, India. Zacharias claims descent from a woman (of the Nambudiri Brahmin caste) and a low caste Boatman. Missionaries spoke to one of his ancestors about Christianity and thereafter the family was converted. Zacharias grew up in a nominal Anglican household, and he himself was an atheist until the age of 17, when he unsuccessfully tried to commit suicide by swallowing poison. While in the hospital, a local Christian worker brought him a Bible and instructed his mother to read to him out of John 14. Zacharias says that it was John 14:19 that touched him and caused him to commit his life to Christ.