Denial of their existence is unscientific insofar as such a denial is a judgement or conclusion which must be based on concrete proof. No one can prove and therefore scientifically claim the non-existence of the invisible realm of existence. A fact which believers can and do observe is that, the stronger one's belief, the deeper and more regular one's worship and the higher one's morality, the more radiant and loveable one's face appears to be. After these preliminary remarks to remove some of the so-called scientific objections to believing in the existence of the spirit, angels, jinn and Satan, we can go on with positive arguments to convince the reader of their existence. Matter serves life in the universe, not the other way round.
Sciences are unable to explain life.
How organic matter grows into life is a mystery for the sciences. Although matter appears to be the basis for life on the earth or serves as a receiver of life, it is evidently not its originator. It is because of the particular features of each spirit that human beings, although formed of the same physical elements, are different from each other in character, countenance, potential, desire and fate. For example, it is through life that a fly or a bird is 'greater' than a mountain. Life enables a honey-bee to claim that the whole earth is its garden to establish relations with all flowers and enter into transactions with them.