What is reality? is it that what we see? what is its origin? If we can influence reality, how do we do this? Interesting questions. If we see that reality is created within each of us, we are also responsible for it. I can recommend a book from Paul Watzlawick to have a “scientific” view on the subject.
Wie wirklich ist die Wirklichkeit?: ... Paul Watzlawick
Of course the book is also available in English 
Firewalk is one of the ways to experience “extreme spirituality”. Science hasn’t been able to prove sufficiently how it works, the best we can say is that it is a matter of mind. If you believe you won’t get hurt, you won’t. Of course, Reality is created by your deepest feelings, thoughts and hopes, therefore it is necessary to have respect for the fire and for the self. It is an interesting experience I can only recommend!
