Man indulges in arrogance in a world where all the things surrounding him are teaching him lessons in obedience. For example, the shadows of material things. The shadow of a thing standing erect falls on the ground. In this way, it symbolizes kneeling down (sajdah). It shows symbolically how a man should bow down before his Creator. Though angels are not visible to man, the running of this immense universe in the most regulated manner proves that the agents appointed by God to run it are extremely powerful. These angels, in spite of being extraordinarily powerful, are totally obedient to God. If they were not so, the system of the universe would not function continuously with so much precision and uniformity. In view of this, to be entirely correct in his behaviour, man can do no other than surrender himself to God, do obeisance to Him and become His most obedient subject.