Mark (who wrote with his pen name Belsebuub) is a British-born author of several books on out-of-body experiences, dreams, self-discovery, and ancient knowledge. He wrote from decades of spiritual and mystical experience. He withdrew from public life in 2010.
An early edition of his book The Astral Codex was a bestseller in its genre, and his book Gazing into the Eternal was a finalist in the USA News Best Book Awards 2009 in Spirituality. He appeared on radio and television programs internationally, including numerous interviews with the BBC, Triple J radio in Australia, Rogers TV in Canada, and Greek national television discussing the Gospel of Judas with leading academics.
Mark started his search into spirituality in the early 1970s and began teaching in 1990. In 2001 he created three popular courses, which ran until 2010, and were all released in book format. They were taken by over 90,000 people in over 100 countries free of charge, both online and in person, and were the most popular of their kind at the time.
He does not receive payment from his books out of principle and when he taught, he did so for free. He provided some of his work on his website Belsebuub.com free of charge, excluding printed books, which were sold by his publisher at cost, and which he does not receive any royalties from.