The Imitation of Christ, by Thomas a Kempis, tr. by William Benham [1886], at sacred-texts.com
"My Son, thou must give all for all, and be nothing of thine own. Know thou that the love of thyself is more hurtful to thee than anything in the world. According to the love and inclination which thou hast, everything more or less cleaveth to thee. If thy love be pure, sincere, well-regulated, thou shalt not be in captivity to anything. Do not covet what thou mayest not have; do not have what is able to hinder thee, and to rob thee of inward liberty. It is wonderful that thou committest not thyself to Me from the very bottom of thy heart, with all things which thou canst desire or have.
2. "Why art thou consumed with vain sorrow? Why art thou wearied with superfluous cares? Stand thou by My good pleasure, and thou shalt suffer no loss. If thou seekest after this or that, and wilt be here or there, according to thine own advantage or the fulfilling of thine own pleasure, thou shalt never be in quiet, nor free from care, because in everything somewhat will be found lacking, and everywhere there will be somebody who opposeth thee.
3. "Therefore it is not gaining or multiplying of this thing or that which advantageth thee, but rather the despising it and cutting it by the root out of thy heart; which thou must not only understand of money and riches, but of the desire after honour and vain praise, things which all pass away with the world. The place availeth little if the spirit of devotion is wanting; nor shall that peace stand long which is sought from abroad, if the state of thy heart is without the true foundation, that is, if it abide not in Me. Thou mayest change, but thou canst not better thyself; for when occasion ariseth and is accepted thou shalt find what thou didst fly from, yea more."
A PRAYER FOR CLEANSING OF THE HEART AND FOR HEAVENLY WISDOM
4. Strengthen me, O God, by the grace of Thy Holy Spirit. Give me virtue to be strengthened with might in the inner man, and to free my heart from all fruitless care and trouble, and that I be not drawn away by various desires after any things whatsoever, whether of little value or great, but that I may look upon all as passing away, and myself as passing away with them; because there is no profit under the sun, and all is vanity and vexation of spirit.(1) Oh how wise is he that considereth thus!
5. Give me, O Lord, heavenly wisdom, that I may learn to seek Thee above all things and to find Thee; to relish Thee above all things and to love Thee; and to understand all other things, even as they are, according to the order of Thy wisdom. Grant me prudently to avoid the flatterer, and patiently to bear with him that opposeth me; for this is great wisdom, not to be carried by every wind of words, nor to give ear to the wicked flattering Siren; for thus do we go safely on in the way we have begun.
(1) Ecclesiastes ii. 11.