…it is necessary that the signs of the perfection of the spirit should be apparent in this world, so that the world of creation may bring forth endless results, and this body may receive life and manifest the divine bounties. So, for example, the rays of the sun must shine upon the earth, and the solar heat develop the earthly beings; if the rays and heat of the sun did not shine upon the earth, the earth would be uninhabited, without meaning, and its development would be retarded. In the same way, if the perfections of the spirit did not appear in this world, this world would be unenlightened and absolutely brutal. By the appearance of the spirit in the physical form, this world is enlightened. As the spirit of man is the cause of the life of the body, so the world is in the condition of the body, and man is in the condition of the spirit. If there were no man, the perfections of the spirit would not appear, and the light of the mind would not be resplendent in this world. This world would be like a body without a soul.
- ‘Abdu’l-Baha (Compilation: ‘The Baha’i Faith’)