Prayer consisting of words alone does not help if the heart does not participate in prayer. God hears only a fervent prayer.
Abba Zoilus of Thebaid was once returning from Mt. Sinai and met a monk who complained to him, that they are suffering much from drought in the monastery. Zoilus said to him: "Why don't you pray and implore God?" The monk replied: "We have prayed and have implored, but there is no rain." To this, Zoilus replied: "It is evident that you are not praying fervently. Do you want to be convinced that it is so?" Having said this, the elder raised his hands to heaven and prayed. Abundant rain fell to the earth. Seeing this, the astonished monk fell to the ground and bowed before the elder, but the elder, fearing the glory of men, quickly fled. The Lord Himself said: "Ask and it will be given you" (Luke 11:9).
In vain are mouths full of prayer if the heart is empty. God does not stand and listen to the mouth but to the heart. Let the heart be filled with prayer even though the mouth might be silent. God will hear and will receive the prayer. For God only listens to a fervent prayer.
- St. Nikolai Velimirovich