Thomas a Kempis, The Imitation of Christ 1.25

Of the zealous amendment of our whole life
 

1. Be watchful and diligent in God's service, and think often why you have renounced the world. Was it not that you might live to God and become a spiritual man? Be zealous, therefore, for your spiritual profit, for you shall receive shortly the reward of your labors, and neither fear nor sorrow shall come any more into your borders. Now shall you labor a little, and you shall find great rest, yea everlasting joy. If you shall remain faithful and zealous in labor, doubt not that God shall be faithful and bountiful in rewarding you. It is your duty to have a good hope that you will attain the victory, but you must not fall into security lest you become slothful or lifted up.
 

2. A certain man being in anxiety of mind, continually tossed about between hope and fear, and being on a certain day overwhelmed with grief, cast himself down in prayer before the altar in a church, and meditated within himself, saying, "Oh! If I but knew that I should still persevere," and presently heard within him a voice from God, "And if you did know it, what would you do? Do now what you would do then, and you shall be very secure." And straightway being comforted and strengthened, he committed himself to the will of God and the perturbation of spirit ceased, neither had he a mind any more to search curiously to know what should befall him hereafter, but studied rather to inquire what was the good and acceptable will of God, for the beginning and perfecting of every good work.
 

3. Hope in the Lord and be doing good, says the Prophet; dwell in the land and you shall be fed with its riches. One thing there is which holds back many from progress and fervent amendment, even the dread of difficulty, or the labor of the conflict. Nevertheless they advance above all others in virtue who strive manfully to conquer those things which are most grievous and contrary to them, for there a man profits most and merits greater grace where he most overcomes himself and mortifies himself in spirit.
 

4. But all men have not the same passions to conquer and to mortify, yet he who is diligent shall attain more profit, although he have stronger passions, than another who is more temperate of disposition, but is rather less fervent in the pursuit of virtue. Two things specially avail unto improvement in holiness, namely firmness to withdraw ourselves from the sin to which by nature we are most inclined, and earnest zeal for that good in which we are most lacking. And strive also very earnestly to guard against and subdue those faults that displease you most frequently in others.
 

5. Gather some profit to your soul wherever you are, and wherever you see or hear good examples, stir yourself to follow them, but where you see anything which is blameworthy, take heed that you do not the same; or if at any time you have done it, strive quickly to amend yourself. As your eye observes others, so again are the eyes of others upon you. How sweet and pleasant is it to see zealous and godly brethren temperate and of good discipline; and how sad is it and grievous to see them walking disorderly, not practising the duties to which they are called. How hurtful a thing it is to neglect the purpose of their calling, and turn their inclinations to things which are none of their business.
 

6. Be mindful of the duties that you have undertaken, and set always before you the remembrance of the Crucified. Truly ought you to be ashamed as you look upon the life of Jesus Christ, because you have not yet endeavored to conform yourself more unto Him, though you have been a long time in the way of God. A religious man who exercises himself seriously and devoutly in the most holy life and passion of our Lord shall find there abundantly all things that are profitable and necessary for him, neither is there need that he shall seek anything better beyond Jesus. Oh! if Jesus crucified would come into our hearts, how quickly, and completely should we have learned all that we need to know!
 

7. He who is earnest receives and bears well all things that are laid upon him. He who is careless and lukewarm has trouble upon trouble, and suffers anguish upon every side, because he is without inward consolation, and is forbidden to seek that which is outward. He who is living without discipline is exposed to grievous ruin. He who seeks easier and lighter discipline shall always be in distress, because one thing or another will give him displeasure.
 

8. O! if no other duty lay upon us but to praise the Lord our God with our whole heart and voice! Oh! if you never had need to eat or drink, or sleep, but were always able to praise God, and to give yourself to spiritual exercises alone; then should you be far happier than now, when for so many necessities you must serve the flesh. O! that these necessities were not, but only the spiritual refreshments of the soul, which alas we taste too seldom.
 

9. When a man has come to this, that he seeks comfort from no created thing, then does he perfectly begin to enjoy God, then also will he be well contented with whatsoever shall happen unto him. Then will he neither rejoice for much nor be sorrowful for little, but he commits himself altogether and with full trust unto God, who is all in all to him, to whom nothing perishes nor dies, but all things live to Him and obey His every word without delay.
 

10. Remember always your end, and how the time which is lost returns not. Without care and diligence you shall never get virtue. If you begin to grow cold, it shall begin to go ill with you, but if you give yourself unto zeal you shall find much peace, and shall find your labor the lighter because of the grace of God and the love of virtue. A zealous and diligent man is ready for all things. It is greater labor to resist sins and passions than to toil in bodily labors. He who shuns not small faults falls little by little into greater. At eventide you shall always be glad if you spend the day profitably. Watch over yourself, stir yourself up, admonish yourself, and howsoever it be with others, neglect not yourself. The more violence you do unto yourself, the more you shall profit. Amen.