The Imitation of Christ, by Thomas a Kempis, tr. by William Benham , at sacred-texts.com
"My Son, thou hast still many things to learn, which thou hast not well learned yet."
2. What are they, Lord?
3. "To place thy desire altogether in subjection to My good pleasure, and not to be a lover of thyself, but an earnest seeker of My will. Thy desires often excite and urge thee forward; but consider with thyself whether thou art not more moved for thine own objects than for My honour. If it is Myself that thou seekest, thou shalt be well content with whatsoever I shall ordain; but if any pursuit of thine own lieth hidden within thee, behold it is this which hindereth and weigheth thee down.
4. "Beware, therefore, lest thou strive too earnestly after some desire which thou hast conceived, without taking counsel of Me; lest haply it repent thee afterwards, and that displease thee which before pleased, and for which thou didst long as for a great good. For not every affection which seemeth good is to be forthwith followed; neither is every opposite affection to be immediately avoided. Sometimes it is expedient to use restraint even in good desires and wishes, lest through importunity thou fall into distraction of mind, lest through want of discipline thou become a stumbling-block to others, or lest by the resistance of others thou be suddenly disturbed and brought to confusion.
5. "Sometimes, indeed, it is needful to use violence, and manfully to strive against the sensual appetite, and not to consider what the flesh may or not will; but rather to strive after this, that it may become subject, however unwillingly, to the spirit. And for so long it ought to be chastised and compelled to undergo slavery, even until it be ready for all things, and learn to be contented with little, to be delighted with things simple, and never to murmur at any inconvenience."