Your enemy, the evil one, the father of lies, does not slumber; and endeavors, by every means open to him, to harden your heart --- to make it false and crafty, to drive out from it faith and hope in God - together with love for Him and love and sympathy for your neighbor - and to occupy you with worldly, temporal interests. Watch yourself, watch the thoughts of your heart, and do not bind yourself in the chains of worldly desires and pleasures. Let your happiness be in the one God and the human soul.
We should zealously cultivate watchfulness, my brethren; and when, our mind purified in Christ Jesus, we are exalted by the vision it confers, we should review our sins and our former life, so that shattered and humbled at the thought of them we may never lose the help of Jesus Christ our God in the invisible battle.
A house roof is held up by the foundations and the rest of the building, and the foundations with the rest of the building are laid to hold the roof - since both are necessary and useful - and neither is the roof built without the foundations and the rest of the house, nor can foundations and walls without a roof make a building fit to live in. So it is with the soul: the grace of the Holy Spirit is preserved by keeping the commandments, and the keeping of commandments is the foundation laid for receiving the gift of God's grace. Neither does the grace of the Holy Spirit remain in us without our obeying the commandments, nor can obeying the commandments be useful and salutary without Divine grace.
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.
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.
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.
Grace is the food and clothing of the saints. It wakens grief in a man's heart, making him dissatisfied and moving him to seek the reason of this dissatisfaction. Grace gives sorrow and grace comforts; showing us the poverty of all things, it engenders in us a repentant sorrow for having fallen short of the love of God... One who is possessed by such sorrow will always grieve, for he thinks of God's offended love and not of the fear of hell. It is a grief of love.
The more wood you pile on a fire the more heat you get, and thus it is with God - the more you think on Him the more you are fired with love and fervor towards Him. He who loves the Lord is always mindful of Him, and remembrance of God begets prayer.
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.
Grace comes immediately to meet some of those who strive, giving them assurance of the earnest of their inheritance, (Eph. 1:14), letting them taste the promised prizes, as if stretching out a loving hand to welcome them and anointing them for further struggles. With others, however, grace waits for the end of the struggle, and prepares for them the crown of patience as well. As one of the God-bearing Fathers says, 'some receive holy rewards before their labors, some during their labors, and some when they depart.'
He who seeks grace from God must, above all, endure temptations and afflictions no matter how they come. Otherwise, if he becomes indignant and doesn't show enough patience during temptation, neither will grace manifest itself, nor will his virtue be perfected or will he be counted worthy of any spiritual gift.
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.