We must strive after a quiet mind. As well might the eye ascertain an object put before it while it is wandering restless up and down and sideways, without fixing a steady gaze upon it, as a mind, distracted by a thousand worldly cares, be able clearly to apprehend the truth. He who is not yet yoked in the bonds of matrimony is harassed by frenzied cravings, and rebellious impulses, and hopeless attachments; he who has found his mate is encompassed with his own tumult of cares; if he is childless, there is desire for children; has he children? Anxiety about their education, attention to his wife, care of his house, oversight of his servants, misfortunes in trade, quarrels with his neighbours, lawsuits, the risks of the merchant, the toil of the farmer. Each day, as it comes, darkens the soul in its own way; and night after night takes up the day's anxieties, and cheats the mind with illusions in accordance. Now one way of escaping all this is separation from the whole world; that is, not bodily separation, but the severance of the soul's sympathy with the body, and to live so without city, home, goods, society, possessions, means of life, business, engagements, human learning, that the heart may readily receive every impress of divine doctrine. Preparation of heart is the unlearning the prejudices of evil converse. It is the smoothing of the waxen tablet before attempting to write on it.
Continually take careful note of your inner intention: watch carefully which way it inclines, and discover whether it is for God and the sake of goodness itself and the benefit of your soul...
It is impossible for the soul to attain anything spiritual and pleasing to God, or to be free of inner sin, without guarding of the mind and purity of heart, in other words, without sobriety... If with God's help we gain something daily through our sobriety, we should take care not to enter into communication with other people without discrimination, lest we suffer loss through our converse with them and are led into temptation.
When someone is beginning the spiritual life, he should not study a lot, but instead watch himself and guard his thoughts. A strong person is the one who chews well, not the one who eats a lot.
Many do good actions, but neglect the mind; they know nothing of the spiritual contests, the victories and defeats. They neglect the mind which is the eye of the soul.
The heart which is constantly guarded, and is not allowed to receive the forms, images and fantasies of the dark and evil spirits, is conditioned by nature to give birth from within itself to thoughts filled with light. For just as coal engenders a flame, or a flame lights a candle, so will God, who from our baptism dwells in our heart, kindle our mind to contemplation when He finds it free from the winds of evil and protected by the guarding of the intellect.
Watch constantly, learning to understand God's law, for this warms the heart with heavenly fire. Guard your lips from the idle word, or empty talk, lest the heart gets used to evil words.
We must vigilantly guard our heart from unfitting thoughts and impressions, according to the word of the writer of Proverbs: ‘Keep thine heart with the utmost care; for out of these are the issues of life,’ (Proverbs 4:23).
Watchfulness cleanses the conscience and makes it lucid. Thus cleansed, it immediately shines like a light that has been uncovered, banishing such darkness. Once this darkness has been banished through constant and genuine watchfulness, the conscience then reveals things hidden from us.
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.
Apostolic teaching, Beloved, exhorts us that we put off the old man with his deeds (Eph. iv. 22; Col. iii. 9), and renew ourselves from day to day by a holy manner of life. For if we are the temple of God, and if the Holy Spirit is a Dweller in our souls, as the Apostle says: You are the temple of the living God (II Cor. vi. 16); we must then strive with all vigilance that the dwelling of our heart be not unworthy of so great a Guest.