Based on the author's work, The unseen realm.
Michael S. Heiser (1963-2023) was a popular Bible teacher, author, and the founding executive director of AWKNG School of Theology. An expert in the Bible and ancient Semitic languages, he wrote numerous books, including The Unseen Realm, Angels, and Demons. For many years, he was scholar-in-residence at Logos Bible Software. He earned a PhD in Hebrew Bible and Semitic languages from the University of Wisconsin-Madison.