Have you realized that the world and worldly cares do not hinder in fulfilling God's commandments, when there is zeal and attention? That silence and retirement from the world are useless, if laziness and negligence prevail?
Watchfulness and the Jesus Prayer, as I have said, mutually reinforce each other, for close attentiveness goes with constant prayer, while prayer goes with close watchfulness and attentiveness of intellect.
According to the teachings of the Holy Fathers, in order to destroy insensibility man needs a constant, patient, uninterrupted activity against insensibility; he needs a constant, pious, and attentive life.
Having guarded ourselves against distractions and worries, let us turn our attention to our body on which mental vigilance is completely dependent. Human bodies differ widely from one another in strength and health. Some by their strength are like copper and iron; others are frail like grass. For this reason everyone should rule his body with great prudence, after exploring his physical powers. For a strong and healthy body, special fasts and vigils are suitable; they make it lighter, and give the mind a special wakefulness. A weak body should be strengthened by food and sleep according to one's physical needs, but on no account to satiety. Satiety is extremely harmful even for a weak body; it weakens it, and makes it susceptible to disease. Wise temperance of the stomach is a door to all the virtues. Restrain the stomach, and you will enter Paradise. But if you please and pamper your stomach, you will hurl yourself over the precipice of bodily impurity, into the fire of wrath and fury, you will coarsen and darken your mind, and in this way you will ruin your powers of attention and self-control, your sobriety and vigilance…
If the mind is strengthened with the strength that it received from the Spirit, first it is purified and sanctified, and learns discrimination in the words that it delivers to the tongue, that they may be without partiality and without self-will, and so the saying of Solomon is fulfilled, `My words are spoken from God, there is nothing forward nor perverse in them.' (Cf. Prov. 8:8) And in another place he says, `The tongue of the wise is healing' (Prov. 12:18), and much besides.
If we use all means and all efforts to avoid death of the body, how much more must we seek to avoid death of the soul. For there is no obstacle for a man wishing to be saved, except negligence and laziness of soul.
Therefore with your whole soul you should acknowledge yourself as worthy of enduring more than you already endure; remember the words which Christ the Savior spoke concerning a good deed done to one's neighbor, words which should apply equally to every offensive word or deed against one's neighbor. Whatever you have done to your neighbor, He says, you have done to Me.
The first duty of a Christian, of a disciple and follower of Jesus Christ, is to deny oneself. To deny oneself means to give up one's bad habits, to root out of the heart all that ties us to the world; not to cherish bad desires and thoughts; to quench and suppress bad thoughts; to avoid occasions of sin; not to do or desire anything from self-love but to do everything out of love for God. To deny oneself means, according to the Apostle Paul, to be dead to sin and the world, but alive to God.
Our Lord and God made flesh has offered us the image of all virtue, as an example to the human race; and to recall us from the ancient fall, has set before us, as in a picture, His all-virtuous life in the flesh. Among many other good examples, He has shown us how, after His baptism, when He went out into the wilderness, it was with fasting that He began His mental wrestling with the devil, who came against Him as an ordinary man. And through this manner of His victory, our Lord has taught us, His unprofitable servants, how we must practice our wrestling against the spirits of evil, that is with humility and fasting and prayer and sobriety: which He observed though He Himself had no need of such things, being God...
The deadly wound consists of every sin that is not repented and confessed, and of falling into despair. This depends on our choice and will. If we do not yield ourselves to the pit of carelessness and despair the devils cannot prevail over us. Even when we have been wounded, if we so wish we may through fervent penitence become more courageous and skillful fighters.