I found its inclusion incomprehensible. I purchased the book and got as far as the third chapter. I learned more from researching the book itself than I did from trying to actually read the thing.

Gurdjieff existed in a time before personal development really became a thing. He did not believe in books as an effective method for change. His technique was primarily interpersonal, he thought one needed a guru to tell them what to do, much as we would today hire a personal trainer to help us work out more effectively.

He survived a terrible automobile accident later on in life and turned his attention to his legacy. He wrote three books, Beelzebub was his first. The intention was to provide a 'textbook' of sorts. Because it was so hard to read, the seeker would be driven to seek out someone to interpret the work for them.

The actual content of the book, when you strip out the intricate allegory and dense terminology, is actually pretty simple. It basically states Gurdjieff's ideas concerning the human condition. The default status of man is waking sleep, one needs inner spiritual work to rouse themselves out of that state.