Supplication has a powerful effect. It almost always yields results; indeed, its results are continuous, especially if it gains universality and is constant. It may even be said that supplication was one of the reasons for the world’s creation.
Supplication is worship. By means of it, God’s servant proclaims his powerlessness and want. The apparent purposes mark the times of the supplication and the supplicatory worship; they are not really the purpose.
The purpose of worship and its benefits look to the hereafter. If its worldly aims are not obtained, it should not be said that the supplication was not accepted, but that the time for it has not yet ended.
From Twenty-Fourth Letter by Master Said Nursi