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.
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.
The more a man's tongue flees verbosity, the more his intellect is illumined so as to be able to discern deep thoughts; for the rational intellect is befuddled by verbosity.
Cultivate patience. Patience is a heavenly gift, a gift from the Heavenly Father... With patience, and love for your fellow men, you become a victor in life's continual trials.
Read often and insatiably the books of the teachers of the Church on divine providence, for they lead the mind to discern the order in God’s creatures and His actions, give it strength, and by their subtleness they prepare it to acquire luminous intuitions and guide it in purity toward understanding of God’s creatures. Read also the Gospels, which God ordained for knowledge for the whole world, that you may find provisions for your journey in the might of God’s providence for every generation, and that your intellect may plunge deeply into wonder at Him. Such reading furthers your aim. Let your reading be done in a stillness which nothing disturbs; be free of all concern for the body and the turmoil of affairs, so that through the sweet understanding which surpasses all the senses you may savor that most sweet taste in your soul which she perceives in herself because of her constant intercourse with these things.
The fact that repentance furnishes hope should not be taken by us as a means to rob ourselves of the feeling of fear, so that one might more freely and fearlessly commit sin. For behold how God in every wise preached fear in all the Scriptures and showed Himself to be a hater of sin.
But if you give a strong body rest and ease and idleness, all the passions dwelling in the soul are intensified. Then, even if the soul has a great desire for good, even the very thought of the good that is desired will be taken from you.
Love of God proceeds from conversing with him; this conversation of prayer comes about through stillness, and stillness comes with the stripping away of the self.
If the Lord delays granting you full victory over your enemies and puts it off to the last day of your life, you must know that He does this for your own good; so long as you do not retreat or cease to struggle wholeheartedly. Even if you are wounded in battle, do not lay down your arms and turn to flight. Keep only one thing in your mind and intention - to fight with all courage and ardor, since it is unavoidable. No man can escape this warfare, either in life or in death. And he who does not fight to overcome his passions and his enemies will inevitably be taken prisoner, either here or yonder, and delivered to death.
A great effort and much toil are needed in prayer before we can reach a state in which our mind is no longer troubled, and so attain the inward heaven of the heart where Christ dwells. As St. Paul says, 'Do you not realize that Christ dwells within you, unless you are worthless?' (cf. 2 Cor. 13:5).
The deeper the contrition, the better. But however deep the contrition, never admit a shadow of doubt about forgiveness. Forgiveness is already fully prepared and the record of all sins has been torn up on the Cross. Repentance and contrition alone are expected of every man, before he too can participate in the power of the redemption of the sins of the world through the Crucifixion.