Thou hast asked about material means and prayer. Prayer is like the spirit and material means are like the human hand. The spirit operateth through the instrumentality of the hand. Although the one true God is the All-Provider, it is the earth which is the means to supply sustenance. "The heaven hath sustenance for you"[Qur'án 51:22] but when sustenance is decreed it becometh available, whatever the means may be. When man refuseth to use material means, he is like a thirsty one who seeketh to quench his thirst through means other than water or other liquids. The Almighty Lord is the provider of water, and its maker, and hath decreed that it be used to quench man's thirst, but its use is dependent upon His Will. If it should not be in conformity with His Will, man is afflicted with a thirst which the oceans cannot quench. (‘Abdu’l-Baha, The Compilation of Compilations, Vol. II, The Importance of Prayer, Meditation and the Devotional Attitude)
