The most important thing in any good effort and the height of all activities is to persevere in prayer, by means of which we can always acquire through supplication the other virtues from God as well.
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.
The Lord commands all men to repent (Matt. 4:17), so that even the spiritual and those making progress should not neglect this injunction and fail to give attention to the smallest and most subtle errors.
There is a sin which is always 'unto death' [1 Jn 5:16]; the sin which we have not repented. Even a saint's prayers will not be heard for the unrepented sin. The person who repents correctly does not imagine that his sins are cancelled through his own effort; but knows that through this effort he makes peace with God.
Christians should judge no one, neither an open harlot, nor sinners, nor dissolute people, but should look upon all with simplicity of soul and a pure eye. Purity of heart, indeed, consists in seeing sinful and weak men and having compassion for them and being merciful.
Continuity of attention produces inner stability; inner stability produces a natural intensification of watchfulness; and this intensification gradually and in due measure gives contemplative insight into spiritual warfare. This in its turn is succeeded by persistence in the Jesus Prayer and by the state that Jesus confers, in which the intellect, free from all images, enjoys complete quietude.
Those who have sinned must not despair. Let that never be. For we are condemned not for the multitude of evils, but because we do not want to repent...
For this world is opposed to the world above, and this present age to the eternity above. The Christian therefore, according to Holy Scripture, must deny the world, and be translated and pass in mind out of this present age, in which the mind is placed and exposed to allurements ever since the transgression of Adam, into another age, and in frame of thought must live in the world of the Godhead above, as it is said, But our conversation is in heaven. (Phil. iii. 20.).
Many are the obstacles that stand in the way of pleasing God; for not merely poverty and obscurity but also riches and honor are trials for the soul. Indeed, to some extent even the solace and ease which grace bestows on the soul can easily become a temptation and a hindrance if the soul is not properly conscious of these effects of grace and does not enjoy them with great circumspection and understanding: for the spirit of evil tries to persuade the soul to relax now it possesses grace, and so contrives to implant in it sluggishness and apathy.
He who wants to cross the spiritual sea is long-suffering, humble, vigilant and self-controlled. If he impetuously embarks on it without these four virtues, he agitates his heart, but cannot cross.
When a man gives God his secret things, that is, his mind and thoughts, not occupying himself elsewhere, nor wandering away, but putting constraint upon himself, then the Lord deems him worthy of mysteries, in greater sanctity and purity, and gives him heavenly food and spiritual drink
There is nothing more efficacious against the wiles of the devil, dearly beloved, than the kindness of forgiveness, and the bountifulness in charity, by means of which sin is either avoided or overcome.