I am not sure if this would be a book topic or not. But I think there is great confusion in the world today about the devil. Many do not believe that he exists as a living entity. I have always had questions about his origination. If God's will is always done in heaven, how was Satan able to reply defiantly "I will not serve. And how was he able to influence so many other spirits to follow him. And there are many questions about his existence today. Does he exist only on earth? Does he exist outside of time? Does he know the future? Our future? Since he is a spirit and we are physical, can he affect us physically? It may or may not be a book, but I think it is definitely a topic that could use some theological truth and clarification.