This prayer should never be absent from you: 'Lord Jesus Christ, Son and Logos of the living God, through the Theotokos and all the Saints, have mercy upon me, Thy sinful and unworthy servant.' (This is the actual Jesus Prayer: 'O LORD JESUS CHRIST, SON OF GOD, HAVE MERCY UPON ME, A SINNER.') Always say this prayer both with your mouth and with your mind, day and night, wherever you may be, whether eating, walking, working, or sitting. Always meditate on it, as it benefits you a great deal, frees you here from every evil, delivers you there from eternal Hell, and renders you worthy of going to Paradise, our heavenly country.
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.
The deadly wound consists of every sin that is not repented and confessed, and of falling into despair. This depends on our choice and will. If we do not yield ourselves to the pit of carelessness and despair the devils cannot prevail over us. Even when we have been wounded, if we so wish we may through fervent penitence become more courageous and skillful fighters.
Take care never to receive Communion while you have anything against anyone, even if this is only a hostile thought. Not until you have brought about reconciliation through repentance should you communicate, [receive the Mysteries]. But you will learn this, too, through prayer.
Go, sell all that belongs to you and give it to the poor and taking up the cross, deny yourself; in this way you will be able to pray without distraction.
Have you realized that the world and worldly cares do not hinder in fulfilling God's commandments, when there is zeal and attention? That silence and retirement from the world are useless, if laziness and negligence prevail?
Some people when praised for their virtue are delighted, and attribute this pleasurable feeling of self-esteem to grace. Others when reproved for their sins are pained, and they mistake this beneficial pain for the action of sin.