Selected quotes from St. Gregory of Sinai:

 
"In whatever work we engage patience gives birth to courage, courage to commitment, commitment to perseverance, and perseverance to an increase in the work done. Such additional labour quells the body's dissolute impulses and checks the desire for sensual indulgence. Thus checked, desire gives rise to spiritual longing, longing to love, love to aspiration, aspiration to ardour, ardour to self-galvanizing, self-galvanizing to assiduousness, assiduousness to prayer, and prayer to stillness. Stillness gives birth to contemplation, contemplation to spiritual knowledge, and knowledge to the apprehension of the mysteries. The consummation of the mysteries is theology, the fruit of theology is perfect love, of love humility, of humility dispassion, and of dispassion foresight, prophecy and foreknowledge. No one possesses the virtues perfectly in this life, nor does he cut off evil all at once. On the contrary, by small increases of virtue evil gradually ceases to exist."
 

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"There are three virtues connected with stillness which we must guard scrupulously, examining ourselves every hour to make sure that we possess them, in case through unmindfulness we are robbed of them and wander far away from them. These virtues are self-control, silence and self-reproach, which is the same thing as humility. They are all-embracing and support one another; and from them prayer is born and through them it burgeons."

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"Authentic prayer - the warmth that accompanies the Jesus Prayer, for it is Jesus who enkindles fire on the earth of our hearts (cf. Luke 12:49) - consumes the passions like thorns and fills the soul with delight and joyfulness. Such prayer comes neither from right or left, nor from above, but wells up in the heart like a spring of water from the life-quickening Spirit. It is this prayer alone that you should aspire to realize and possess in your heart, always keeping your intellect free from images, concepts and thoughts. And do not be afraid, for He who says 'Take heart; it is I; do not be afraid' (Matt. 14:27), is with us - He whom we seek and who protects us always. When we invoke God we must be neither timid nor hesitant."