The soul of all practices in the Lord is vigilance. Without vigilance, all these practices are fruitless. He who is desirous of saving himself must so establish himself that he might remain continuously vigilant toward himself, not only in solitude, but also under conditions of distraction, into which he is sometimes unwillingly drawn by circumstances.
The belly when filled with all kinds of food gives birth to seeds of wantonness, nor can the mind, when choked with the weight of food, keep the guidance and government of the thoughts. For not only is drunkenness with wine wont to intoxicate the mind, but excess of all kinds of food makes it weak and uncertain, and robs it of all its power of pure and clear contemplation. The cause of the overthrow and wantonness of Sodom was not drunkenness through wine, but fullness of bread. Hear the Lord rebuking Jerusalem through the prophet. 'For how did thy sister Sodom sin, except in that she ate her bread in fullness and abundance?' (Ezek. xvi. 49)
If the saints, who had attained passionlessless, had to be vigilant over themselves so as not to fall from their state of grace - then all the more is daily attentiveness and concern over our eternal salvation necessary for us sinners. The fact that we are still alive means that the Lord patiently endures our sins and awaits our amendment, and if someone lawfully labors for his salvation, the Lord takes him at a time when he becomes worthy of God’s mercy.
No Christian believing rightly in God should ever be off his guard. He should always be on the look-out for temptation, so that when it comes he will not be surprised or disturbed, but will gladly endure the toil and affliction it causes, and so will understand what he is saying when he chants with the prophet: 'Prove me, O Lord, and try me' (Ps. 26:2 LXX). For the prophet did not say, 'Thy correction has destroyed me,' but, 'it has upheld me to the end' (Ps. 18:35 LXX).
If Nabuzardan, the court cook of the King of the Babylonians, had not gone to Jerusalem, then the Temple would not have burned (cf. 2 Kings 24), That is to say, a person’s mind is not attacked by the flames of carnal pleasures, if a person is not conquered by gluttony.
It is not food that is evil but gluttony; not childbearing but fornication; not money but cupidity; not glory but vainglory. If this be so there is no evil in anything that is, except wrong use, which results from our mind neglecting to cultivate our nature (the powers of the soul, and their right direction).
Smoke from wood kindling a fire troubles the eyes; but then the fire gives them light and gladdens them. Similarly, unceasing attentiveness is irksome; but when, invoked in prayer, Jesus draws near, He illumines the heart; for remembrance of Him confers on us spiritual enlightenment and the highest of all blessings.
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...
If the passions strike you from time to time, this should not distress you. We must continue the 'unseen warfare' all our lives. The battle itself is not a problem; there is trouble only if we become weak in it. If this does not happen, our spiritual life is in good order. The peace that is with you in battle bears witness to this. But we must beware that we do not feel a different kind of peace, the kind one feels when there is no battle. This kind of peace is dangerous. It indicates that the enemy has done away with open battle and wants to build an invisible and clever snare for us! In cases like this one must intensify one's usual vigilance and sobriety! Do not weaken in any way!
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.
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).
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.
Even if thy soul should suffer somewhat from an offense, keep the sorrow within thyself. For it is said: 'Within me my heart is troubled' (Psalm 142:4), that is, the passion has not come out, but has been humbled like a wave that has broken up on the shore. Calm thy raging heart. Let thy passions be ashamed at the presence of reason in thee, as playful children are ashamed before a man commanding respect.