[Hay'a] is a word that reflects a kind of respectful shyness, deference, and reverence. It is not a shyness that proceeds from fear but from appreciation. It is a kind of humility in the face of excellence. Hay'a is also a word full of concern, a concern for God's glory as reflected in creation and in all other creatures.
Ammar says quite simply that it is the absence of hay'a that is causing the world's ecological crisis. The absence of hay'a in Islam and in the rest of the world is the cause of the disparity between rich and poor, the success of corporations in stimulating overconsumption and the maldistribution of resources, wars, the intolerance of ethnic diversity, oppression of women, infant mortality, and crime.
— Daniel C. Maguire, Sacred Energies