These are of two kinds: their functions in the physical world, and the spiritual development of man.
In the physical world, the working of nature is governed by laws, as science has shown by discovering many of these laws. Islam teaches that these laws have been devised by God, and the angels - the obeying functionaries of God - put them into action.
On the spiritual side, the angels communicate God's revelation to the Prophets and other righteous ones, bring comfort and strength to the hearts of true believers, and inspire noble thoughts in the minds of all persons. They do this, of course, by acting through the spiritual senses of human beings, not their physical senses like the eyes or ears.
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What is an Angel? An angel is generally a supernatural being found in various religions and mythologies. In Abrahamic religions, angels are often depicted as benevolent celestial beings who act as intermediaries between God or Heaven and Humanity. Other roles of angels include protecting and guiding human beings, and
carrying out God's tasks. Within Abrahamic religions, angels are often organized into hierarchies, although such rankings may vary between sects in each religion, and are given specific names or titles, such as Gabriel or 'Destroying angel'.