Some people think that writing this topic is writing about a topic that is from the periphery of knowledge. They approve of humans going over this topic in the quickest of fashions and not giving it too much thought. They think that the benefits that accrue from such a study are very limited. Furthermore, they believe that being ignorant of this topic is not harmful at all.
However, I am not delving into something distant. Humans today spend billions of dollars with which they could build cities or countries and end poverty in the farthest reaches of the world -- and, instead, they spend that money on research to discover if there is life or if life is possible on nearby planets. Scientists spend a great deal of their time and resources on such a question. What about an existence that is known to be living and thinking, and that lives right here with us on our earth? They live in our houses and they eat and drink with us. In fact, they even spoil our thoughts and our hearts. They drive us to destroy our own selves and to spill each others' blood.
No price can be put on the importance of the texts of the Qur'an and authentic hadith that have reached us, giving us knowledge of this matter. Those texts uncover for us the secrets of that existence: the world of the jinn.