Prayer with words is of no use if the heart does not participate. God only hears prayer from the heart. Abba Zoilos of the Thebaid, returning once from Mount Sinai, met a monk who complained that, in the monastery, they were greatly suffering from drought.
Zoilos asked: ‘Why don’t you pray to God, and implore Him?’ The monk replied: ‘We have prayed and implored, but there is no rain!’ To this Zoilos answered: ‘It is obvious that you are not praying from the heart. Do you want to be convinced that this is so?’ And, thus speaking, the elder raised his hands to heaven and began to pray, and abundant rain fell onto the earth. Seeing this, the marvelling monk fell to the ground before the elder and did him reverence, but the elder, fearing the praise of men, quickly fled from him. ‘Ask, and it shall be given you, said the Lord Himself. But vain are mouthsful of prayers if the heart is empty. God does not stand and listen to the lips but to the heart. Let the heart be filled with prayer and the lips be silent. God will hear and receive the prayer, for He only hearkens to heartfelt prayer.
St. Nikolai Velimirovich