Note the Saint’s humility in the last sentence.
He that does not believe in the God Who saves is in difficult circumstances, but is faint-hearted; he that does not wish to render glory to God, that represents Him as not vigilant, but sleeping, not all-powerful and not merciful, thinks falsely of the God of Truth, and thus sins grievously. Especially inexcusable are faint-heartedness and unbelief in the man who has already been deemed worthy of often receiving marvelous help from God the Savior. Oh how great a sinner I am!
St. John of Kronstadt
Initially one thinks this is the typical “Hey all you sinners, stop it!” quote. While it is that, it is also St. John’s look in the mirror.
Men have fallen into unbelief because they have either completely lost the spirit of prayer, or they never had it at all, nor have it now- in short, because they do not pray. The prince of this world has full scope for action in the hearts of such men; he becomes their master. They have not asked and do not ask God’s grace in prayer (for God’s gifts are only given to those who ask and seek) and thus their hearts, corrupt by nature, become dried up without the vivifying dew of the Holy Spirit, and at last from their extreme dryness they take fire, and blaze with the infernal flame of unbelief and various passions, and the Devil only knows how to inflame the passions that keep up this terrible fire, and triumphs at the sight of the ruin of the unfortunate souls that redeemed by the blood of Him Who has trampled the power of Satan underfoot.
St. John of Kronstadt
One must force oneself, even against one’s will, to prayer and to every good.
Elder Parfeny, Spiritual Counsels
It is the task of unceasing watchfulness – and one of great benefit and help to the soul – to see the mental images of evil thoughts as soon as they are formed in the mind. The task of rebuttal is to counter and expose such thoughts when they attempt to infiltrate our mind in the form of an image of some material thing. What instantly extinguishes and destroys every demonic concept, thought, fantasy, illusion and idol is the invocation of the Lord. And in our mind we ourselves can observe how our great God, Jesus, triumphs over them all, and how He avenges us, poor, base and useless as we are.
St. Hesychios the Presbyter, on watchfulness and holiness, Philokalia
We have learned from experience that for one who wishes to purify his heart it is a truly great blessing constantly to invoke the name of the Lord Jesus Christ against his intelligible enemies.
Notice how what I speak of from experience concurs with the testimony of Scripture. It is written: ‘Prepare yourself, O Israel, to call upon the name of the Lord your God’ (cf. Amos 4:12. lxx);and the Apostle says: ‘Pray without ceasing’ ( 1 Thess. 5:17). Our Lord Himself says: ‘Without Me you can do nothing. If a man dwells in Me, and I in him, then he brings forth much fruit’; and again: ‘If a man does not dwell in Me, he is cast out as a branch’ (John 15:5–6). Prayer is a great blessing, and it embraces all blessings, for it purifies the heart, in which God is seen by the believer.
St. Hesychios the Presbyter, Philokalia, #173
The more the rain falls on the earth the softer it makes it;
similarly, Christ’s holy name gladdens theearth of our heart the
more we call upon it.
St Hesychius the Priest, On Watchfulness and Holiness, #41
The mystery of prayer is not consummated at a certain specific time or place. For if you restrict prayer to particular times or places, you will waste the rest of the time in vain pursuits. Prayer may be defined as the intellect’s unceasing intercourse with God. Its task is to engage the soul totally in things divine, its fulfillment – to adapt the words of St Paul (cf. 1 Cor. 6:17) – lies in so wedding the mind to God that it becomes one spirit with Him.
-St. Nikitas Stethatos, Philokalia