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.
St. John Chrysostom, in considering the misfortune both of parents that neglect the good upbringing of their children and of the children not well brought up, says this, 'Parents that neglect to bring up their children as Christians, are most heinous murderers of children' (Homily 3, 'Against Those that Slander the Monastic Life '). For child-killers separate the body from the soul, but these parents cast them both soul and body info fiery Gehenna. It is impossible to escape from the former death according to natural law, but it would be possible to escape from the latter death were the negligence of the parents not to blame for it. Moreover, once it comes, the Resurrection is able to abolish bodily death, but nothing can overturn spiritual destruction. Therefore, parents, listen to the word of the Lord, 'Bring up your children in the nurture and admonition of the Lord' (Eph. 6:4).
As a man cannot remain unscathed who spares his enemy on the field of battle, so a man engaged in spiritual warfare cannot save his soul if he spares his body.
When the flesh flourishes, the soul fades; when the flesh has full liberty, the soul is straitened; when the flesh is satiated, the soul hungers; when the flesh is adorned, the soul is deformed; when the flesh overflows with laughter, the soul is surrounded by misfortune; when the flesh is in the light, the soul is in darkness...
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…
