Though {Christ} was the object of derision He was not angry, and are you annoyed? He submitted to being spat upon, struck and scourged, and yet you cannot endure a harsh word! He accepted the cross and a shameful death and the agonies of the nails; do you refuse to perform the lowliest services? How will you be a partaker in His glory (1 Pet. 5:1) when you refuse to be a partaker of His shameful death?
("Symeon the New Theologian: The Discourses", p. 293)
As he daily advances {in his keeping of the Lord's commandments} he will notice how thoughts of the passions to which he is prone are gradually withdrawing, then how these passions themselves diminish, and how the heart is softened and comes to humility; then in turn how the heart gives rise to thoughts that bring about humbleness of mind. But yet as he perceives this he will scarcely thereby arrive at compunction and tears. Nevertheless he arrives at this through many tribulations (Acts 14:22), and the more he is humbled the more he feels compunction. Humiliation brings about affliction, but affliction feeds the humility that is its source and makes it grow. This activity, which is exercised by the fulfilling of the commandments, washes away -- what a marvel! -- every stain from the soul.
("Symeon the New Theologian: The Discourses", pp. 187-188)
It is in faith that hope is planted, and in this soil it is watered by penitence and tears; then, as Thy light shines on it, it takes root and grows well. Then Thou Thyself, O good Craftsman and Creator, coming with the knife of trials -- that is, humility -- takest away the superfluous shoots of thoughts that rise high in the air. (cf. Jn. 15:1-2).
("Symeon the New Theologian: The Discourses", p. 376)
When a man's soul has been purified by tears, and in proportion to his repentance and fulfillment of the commandments, he is first deemed worthy of knowing by grace what is proper to him and his entire self. Then, after much intense purification and profound humility, he begins little by little to perceive in some obscure way things which concern God and the divine, and, to the degree that he perceives, he is wounded to the quick and acquires yet greater humility, deeming himself entirely unworthy of the knowledge and revelation of such mysteries. Thus, too, guarded by such humility as by a fortress wall, he abides within it unwounded by presumptuous thoughts, grows daily in faith, in hope, and in love for God, beholding clearly his progress with the increase of his knowledge and of his ascent. When he attains to a full measure of the maturity of the fulness of the knowledge of Christ, then he will conduct himself as one who neither has nor knows anything, and will consider himself as a useless and unworthy servant. And, what is then astonishing and beyond nature -- or, better is quite according to nature -- he will think that there is no man in all the world lesser or more a sinner than himself.
("On the Mystical Life (Vol. 2)", pp. 127-128)
However great your zeal and many the efforts of your asceticism, they are all in vain and without useful result unless they attain to love in a broken spirit (Ps. 51:17, Ps. 34:18).
("Symeon the New Theologian: The Discourses", p. 45)
Since according to the divine Apostle it is "Not because of works, lest any man should boast" [Eph 3:9] that salvation comes to us who believe, we must not be confident at all in our works -- I mean fasting and vigils, sleeping on the ground, hunger and thirst, binding the body with irons or troubling it with hair shirts. These things are nothing at all... {God} longs instead for a broken spirit, a humbled and contrite heart, and for us always to speak our heart to Him with humility: "Who am I, my Master and God, that You came down and took flesh and died for me, so that You could deliver me from death and corruption, and make me a communicant and participant of Your glory and divinity?" When, according to the invisible movements of your heart, you find yourself in this state, you will discover Him immediately embracing you and kissing you mystically, and bestowing on you a right spirit in your inward parts, a spirit of freedom and of remission of your sins. Nor this alone, but crowning you as well with His gifts, He will make you glorious with wisdom and knowledge.
What else is so dear to God and welcome as a contrite and humble heart, and pride laid low in a spirit of humility? It is in such a condition of soul that God Himself comes to dwell and make His rest, and that every machination of the devil remains ineffective. All the corrupting passions of sin vanish completely.
("On the Mystical Life (Vol. 2)", pp. 109-110)