The Imitation of Christ, by Thomas a Kempis, tr. by William Benham , at sacred-texts.com
"My Son, let not the labours which thou hast undertaken for Me break thee down, nor let tribulations cast thee down in any wise, but let my promise strengthen and comfort thee in every event. I am sufficient to reward thee above all measure and extent. Not long shalt thou labour here, nor always be weighed down with sorrows. Wait yet a little while, and thou shalt see a speedy end of thine evils. An hour shall come when all labour and confusion shall cease. Little and short is all that passeth away with time.
2. "Do earnestly what thou dost; labour faithfully in My vineyard; I will be thy reward. Write, read, sing, weep, be silent, pray, endure adversities manfully; eternal life is worthy of all these conflicts, yea, and of greater. Peace shall come in one day which is known to the Lord; which shall be neither day nor night,(1) but light eternal, infinite clearness, steadfast peace, and undisturbed rest. Thou shalt not say then, Who shall deliver me from the body of this death?(2) nor cry out, Woe is me, for my sojourning is prolonged,(3) because death will be utterly destroyed, and there shall be salvation which can never fail, no more anxiety, happy delight, sweet and noble society.
3. "Oh, if thou sawest the unfading crowns of the Saints in heaven, and with what great glory they now rejoice, who aforetime were reckoned by this world contemptibly and as it were unworthy of life, truly thou wouldst immediately humble thyself even to the earth, and wouldst desire rather to be in subjection to all, than to have authority over one; nor wouldst thou long for pleasant days of this life, but wouldst more rejoice to be afflicted for God's sake, and wouldst esteem it gain to be counted for nought amongst men.
4. "Oh, if these things were sweet to thy taste, and moved thee to the bottom of thine heart, how shouldst thou dare even once to complain? Are not all laborious things to be endured for the sake of eternal life? It is no small thing, the losing or gaining the Kingdom of God. Lift up therefore thy face to heaven. Behold, I and all My Saints with Me, who in this world had a hard conflict, now rejoice, are now comforted, are now secure, are now at peace, and shall remain with Me evermore in the Kingdom of My Father."
(1) Zechariah xiv. 7. (2) Romans vii. 24. (3) Psalm cxx.