May 26

As we… reflect with broad minds upon this infinite universe, we observe that motion without a motive force, and an effect without a cause are both impossible; that every being hath come to exist under numerous influences and continually undergoeth reaction. These influences, too, are formed under the action of still other influences. For instance, plants grow and flourish through the outpourings of vernal showers, whilst the cloud itself is formed under various other agencies and these agencies in their turn are reacted upon by still other agencies. For example, plants and animals grow and develop under the influence of what the philosophers of our day designate as hydrogen and oxygen and are reacted upon by the effects of these two elements; and these in turn are formed under still other influences. The same can be said of other beings whether they affect other things or be affected. Such process of causation goes on, and to maintain that this process goes on indefinitely is manifestly absurd. Thus such a chain of causation must of necessity lead eventually to Him who is the Ever-Living, the All-Powerful, who is Self-Dependent and the Ultimate Cause. This Universal Reality cannot be sensed, it cannot be seen. It must be so of necessity, for it is All-Embracing, not circumscribed, and such attributes qualify the effect and not the cause. 
(‘Abdu’l-Baha, ’Tablet to August Forel’)