There are three ways to get there from here. One is to have what has traditionally been called a religious experience discussed by William James and others, sometimes experienced by us as human beings. That feeling can come from drugs, from LSD or mushrooms, psychedelic mushrooms,. And it appears from your book that it also can come from stimulating certain parts of the brain.
Neurologist and author Robert Burton talks about his book, On Being Certain, with EconTalk host Russ Roberts. Burton explores our need for certainty and the challenge of being skeptical about what our brain tells us must be true. Where does what Burton calls "the feeling of knowing" come from? Why can memory lead us astray? Burton claims that our reaction to events emerges from competition among different parts of the brain operating below our level of awareness. The conversation includes a discussion of the experience of transcendence and the different ways humans come to that experience.