Sayings of the Ascetics about the Prayer

The Elders of Optina Monastery

Concerning that which Brings us Close to God

Prayer

111.             Do not forsake prayer, for just as the body becomes weak when it is deprived of food, so also the soul when it is deprived of prayer draws nigh to weakness and noetic death.
(St. Gennadius of Constantinople, The Golden Chain, 44)

112.             -128. Consistently pray in all things, so that you might not do anything without the help of God ... Whoever does or busies himself with anything without prayer does not succeed in the end. Concerning this, the Lord said: "Without Me you can't do anything". (John 15:5)
(St. Mark the Ascetic, Homilies, 2.94,166)

129.             Whatever we do or say without prayer always ends up either sinful or harmful and convicts us through the deeds in some mysterious way.
(St. Mark the Ascetic, Homilies, 2.108)

130.             The prayer of one who does not consider himself a sinner is not accepted by the Lord.
(St. Isaac the Syrian, Homilies, 55)

131.             God hears and fulfills the prayer of a man who fulfills His commandments. "Hear God in His commandments," says St. John Chrysostom, "So that He might hear you in your prayers." A man who keeps the commandments of God is always wise, patient, and sincere in his prayers. Mystery of prayer consists in the keeping of God's commandments.
(St. Justin Popovich, Explanation of I John, 3:22)

132.             Give your intentions in prayer to God, Who knows everyone, even before our birth. And do not ask that everything will be according to your will, because a man does not know what is profitable for him. But say to God: Let Thy will be done! For He does everything for our benefit.
(St. Gennadius of Constantinople, The Golden Chain, 47)

133.             Everyone who asks something of God and does not receive it doubtless does not receive it for one of these reasons: either because they ask before the time, or they ask unworthily, or out of vainglory, or because if they received what they asked they would become proud or fall into negligence.
(St. John of the Ladder, Ladder, 26.60)

134.             Whoever wants to approach prayer without a guide, and proudly thinks that he can learn from books, and won't go to an elder, is already halfway into delusion. But the Lord helps the humble, and if there is no experienced guide, and he goes to a confessor, whoever he may be, then the Lord will cover him because of his humility.
(St. Silouan the Athonite, Writings, II.1)

135.             If, at the time when the mind is praying it is distracted by any extraneous thought or worry about anything, then this prayer is not called pure.
(St. Isaac the Syrian, Homilies, 16)

136.             If you become proud when you receive what you ask in prayer, then it is obvious that your prayer was not to God, and you did not receive help from Him, but the demons were working with you in order to exalt your heart; For when help is given from God, the soul is not exalted, but is all the more humbled, and she is amazed at the great mercy of God, how merciful He is to sinners.
(St. Barsanuphius the Great, Instructions, 418)

137.             When God wants to have mercy on someone, He inspires someone else to pray for him, and He helps in this prayer.
(St. Silouan the Athonite, Writings, XX.9)

138.             In times of affliction, unceasingly call out to the merciful God in prayer. The unceasing invocation of the name of God in prayer is a treatment for the soul which kills not only the passions, but even their very operation. As a doctor finds the necessary medicine, and it works in such a way that the sick person does not understand, in just the same way the name of God, when you call upon it, kills all the passions, although we don't know how this happens.
(St. Barsanuphius the Great, Instructions, 421)

source