When you intend to do something and see that your thought is perturbed, and if after invoking God's Name it remains perturbed even by a hair's breadth, know from this that the action you mean to commit is from the evil one and refrain from commiting it. For nothing done with perturbation is pleasing to God.
At this point the zealous man looks inward, and what do you think he finds there? Ceaseless wandering of thoughts, constant onslaughts from the passions, hardness and coldness of heart, obstinacy and disobedience, desire to do everything according to his own will. In a word, he finds everything within himself in a very bad state. And seeing this, his zeal is inflamed, and he now directs strenuous efforts to the development of his inner life, to controlling his thoughts and the dispositions of his heart. From directions on inner spiritual life he discovers the necessity of paying attention to oneself, of watching over the movements of the heart. In order not to admit to anything bad, it is necessary to preserve the remembrance of God. And so he sets to work to achieve this remembrance. But his thoughts can no more be arrested than the wind; his bad feelings and worthless impulses can no more be evaded than the stench of a corpse; his mind, like a wet and frozen bird, cannot rise to the remembrance of God. What is to be done? Be patient, they say, and go on working. Patience and labor are exercised, but all within remains the same. At last someone of experience is found who explains that all is inwardly in disorder because the forces within are divided: mind and heart each go their own way. Mind and heart must be united; then wandering of thoughts will cease, and you will gain a rudder to steer the ship of your soul, a lever by which to set in movement all your inner world. But how can one unite mind and heart? Acquire the habit of praying these words with the mind in the heart, 'Lord Jesus Christ, Son of God, have mercy upon me'. And this prayer, when you learn to perform it properly, or rather when it becomes grafted to the heart, will lead you to the end which you desire. It will unite your mind with your heart, it will cut off your wandering thoughts, and give you the power to govern the movements of your soul.
Peter was first given the keys, but then he was allowed to fall into the sin of denying Christ; and so his pride was humbled by his fall. Do not be surprised, then, if after receiving the keys of spiritual knowledge you fall into various evil thoughts. Glorify our Lord, for He alone is wise: through setbacks of this kind He restrains the presumption that we tend to feel because of our advance in the knowledge of God. Trials and temptations are the reins whereby God in His providence restrains our human arrogance.
If the main goal of the repentant sinner should be total, light-bearing and blessed communion with God, then the main hindrance to this is the existence of the passions still active and working in him - the virtues being as yet unsealed in him - and the unrighteousness of his powers. Therefore his main work upon conversion and repentance should be the uprooting of the passions and sealing the virtues - in a word, correcting himself.
Fire makes iron impossible to touch, and likewise frequent prayer renders the intellect more forceful in its warfare with the enemy. That is why the demons strive with all their strength to make us slothful in attentiveness to prayer, for they know that prayer is the intellect's invincible weapon against them.
If thou, being offended by anything, dost sense that grief and wrath have seized thee, preserve silence, and say naught until unceasing prayer pacifies thine heart.
The humility which in due time and by God's grace, after many struggles and tears, is given by heaven to those who seek it is something incompararably stronger and higher than the sense of abasement felt by those who have lapsed from holiness. This higher humility is granted only to those who have attained true perfection and are no longer under the sway of sin.
My brother, the passions are afflictions; and so the Lord does not excommunicate us because of them, but He says: 'Call upon me in the time of affliction; and I will deliver thee, and thou shalt glorify me'. Therefore, when beset by any kind of passion, there is nothing more useful than to call upon the Name of God. All we can do, weak as we are, is to flee for refuge to the Name of Jesus. For the passions, being demons, retreat if this Name is invoked.
The incessant invocation of God's name is a medicine which mortifies not just the passions, but even their influence. Just as the physician puts medications or dressings on a wound that it might be healed, without the patient even knowing the manner of their operation, so also the name of God, when we invoke it, mortifies all passions, though we do not know how that happens.
As it is not possible to walk without feet or fly without wings, so it is impossible to attain the Kingdom of Heaven without the fulfillment of the commandments.
Please put this commandment into practice. Cultivate love towards the Person of Christ to such an extent that, when you pronounce His name, tears fall from your eyes. Your heart must really burn. Then He will become your teacher. He will be your Guide, your Brother, your Father, and your Elder.
Acquire humility, which scorches the demons, obedience, which opens the door for the Son of God to enter a man, faith which saves a man, hope which makes him unashamed; and love which lets not a man fall away from God.
Set your sight on heaven and order every step of your life so that it will be a step in that direction. It seems to me that it is all so simple, and yet so all-embracing.
Do not judge and do not belittle anyone, because from this the heart grows faint and the mind is blinded, and from this, negligence appears and unfeelingness of heart is born. Keep ceaseless vigil, learning in the law of God, for through this the heart is warmed by heavenly fire, as is said: 'In my meditation a fire was kindled.'
If the base of a felled tree that has grown old in the earth and rock ‘will bud at the scent of water . . . like a young plant’ (Job 14:9), it is also possible for us to be awakened by the power of the Holy Spirit and to flower with the incorruptibility that is ours by nature, bearing fruit like a young plant, even though we have fallen into sin.