Prayer: It is either effective or a work for idiots (Spurgeon)

We find a powerful reason for expecting prayer to be effective in the fact that it is an institution of God. In God's Word we are over and over again commanded to pray. God's institutions are not folly. Can I believe that the infinitely wise God has ordained for me an exercise that is ineffective and is no more than child's play? Does He tell me to pray, and yet does prayer have no more of a result than if I whistled to the wind or sang to a grove of trees? If there is no answer to prayer, prayer is a monstrous absurdity, and God is the author of it, which it is a blasphemy to assert. Only a fool will continue to pray when you have once proved to him that prayer has no effect with God and never receives an answer. If it is indeed true that its effects end with the man who prays, prayer is a work for idiots and madmen, not for sane people! - C.H. Spurgeon, "The Power in Prayer"