The key to Divine gifts is given to the heart by love of neighbor, and, in proportion to the heart's freedom from the bonds of the flesh, the door of knowledge begins to open before it.
Just as we must beware of overeating, so too we must beware of excessive temperance or abstinence. Excessive temperance weakens the body, destroys wakefulness, coolness and freshness which are indispensable for vigilance, and which fade and weaken when the physical powers succumb and fail. If you force a weak body to labor beyond its powers, you subject your soul to double darkness, and lead it into confusion (and not relief)...
Do not oppose the thoughts, which the enemy sows in you, but rather cut off all converse with them by prayer to God. We have not always strength enough so to oppose hostile thoughts as to stop them; on the contrary, in such attempts they frequently inflict us with a wound that is long in healing.
Praise God continually with spiritual hymns and always remain in meditation and in this way you will be able to bear the burden of the temptations that come upon you. A traveler who is carrying a heavy load pauses from time to time and draws in deep breaths; it makes the journey easier and the burden lighter.
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.
You must flee from sensual things. Verily, every time a man comes close to a struggle with sensuality, he is like a man standing at the edge of a deep lake, and the enemy throws him in whenever he likes. But if the man lives far from sensual things, he is like one who stands at a distance from the lake, so that even if the enemy entices him in order to throw him to the bottom, God sends him help at the very moment that the enemy is drawing him away and doing him violence.
It is impossible for the soul to be liberated from turbulent thoughts without the virtue of non-possessiveness. And without peace of the bodily senses it is impossible for the soul to have a peaceful intellect. And if it does not come into temptations it will not acquire wisdom of the Holy Spirit. And without laborious and persistence in reading, it will not come to the discernment of thoughts. And without the stillness of thoughts, the intellect cannot move to seek the hidden mysteries of God.