The Imitation of Christ, by Thomas a Kempis, tr. by William Benham , at sacred-texts.com
"My Son, speak thou thus in every matter, 'Lord, if it please Thee, let this come to pass. Lord, if this shall be for Thine honour, let it be done in Thy Name. Lord, if thou see it good for me, and approve it as useful, then grant me to use it for Thy honour. But if thou knowest that it shall be hurtful unto me, and not profitable for the health of my soul, take the desire away from me'! For not every desire is from the Holy Ghost, although it appear to a man right and good. It is difficult to judge with certainty whether a good or an evil spirit move thee to desire this or that, or whether thou art moved by thine own spirit. Many have been deceived at the last, who seemed at the beginning to be moved by a good spirit.
2. "Therefore, whatsoever seemeth to thee desirable, thou must always desire and seek after it with the fear of God and humility of heart, and most of all, must altogether resign thyself, and commit all unto Me and say, 'Lord, thou knowest what is best; let this or that be, according as Thou wilt. Give what Thou wilt, so much as Thou wilt, when Thou wilt. Do with me as Thou knowest best, and as best shall please Thee, and as shall be most to Thine honour. Place me where Thou wilt, and freely work Thy will with me in all things. I am in Thine hand, and turn me in my course. Behold, I am Thy servant, ready for all things; for I desire to live not to myself but to Thee. Oh, that I might live worthily and perfectly.'"
A PRAYER TO BE ENABLED TO DO GOD'S WILL PERFECTLY
3. Grant me Thy grace, most merciful Jesus, that it may be with me, and work in me, and persevere with me, even unto the end. Grant that I may ever desire and wish whatsoever is most pleasing and dear unto Thee. Let Thy will be mine, and let my will alway follow Thine, and entirely accord with it. May I choose and reject whatsoever Thou dost; yea, let it be impossible for me to choose or reject except according to Thy will.
4. Grant that I may die to all worldly things, and for Thy sake love to be despised and unknown in this world. Grant unto me, above all things that I can desire, to rest in Thee, and that in Thee my heart may be at peace. Thou art the true peace of the heart, Thou alone its rest; apart from Thee all things are hard and unquiet. In Thee alone, the supreme and eternal God, I will lay me down in peace and take my rest.(1) Amen.
(1) Psalm iv. 9.