In short, these three states may be called the natural, moral and spiritual states of man. As the natural urges of man become very dangerous when they are roused and often destroy the moral and spiritual qualities, they are described in God's Holy Book as the self that incites to evil. The answer is that according to the Holy Quran the natural state of man has a very strong relationship with his moral and spiritual states, so much so that even a person's manner of eating and drinking affects his moral and spiritual states. If the natural state of a person is subjected to the control of the directions of divine law it becomes his moral state and deeply affects his spirituality, as is said that whatever falls into a salt mine is converted into salt. That is why the Holy Quran has laid stress on physical cleanliness and postures, and their regulation in relation to all worship and inner purity and spiritual humility.
Reflection confirms that physical conditions deeply affect the soul.
For instance, when our eyes are filled with tears, even if the tears are artificially induced, the heart is immediately affected and becomes sorrowful. In the same way, when we begin to laugh, even if the laughter is artificially induced, the heart begins to feel cheerful. It has also been observed that phsyical prostration in prayer induces humility in the soul. As a contrast when we draw ourselves up physically and strut about with our neck raised and our breast pushed forward, this attitude induces a mood of arrogance and vain glory. These instances establish clearly that physical conditions certainly affect spiritual conditions.