Some people think that writing about this topic is writing about a matter that should remain on the periphery of knowledge. They believe in going over this topic in the quickest of fashions and not giving it too much thought. They think that the benefits of such a study are very limited, and that being ignorant of this topic is not harmful at all. However, this is not an irrelevant matter. Humans today spend billions of dollars, with which they could develop countries and end poverty in the farthest reaches of the world, on research to discover whether there is any possibility of life on nearby planets. Scientists spend a great deal of their time and resources on this question. What about living beings that are known to exist right there with us on earth? They live in our houses and they eat and drink with us. In fact, they affect our thoughts and our hearts and even drive us to destroy our own selves and to spill one another’s blood. No price can be put on the importance of the texts of the Qur’an and authentic hadeeth that have reached us, giving us knowledge of this matter. Those texts uncover for us the secrets of theses fellow-creatures; the world of the jinn.