We do not all have the same vices to conquer, the same evil desires to put to death. The one who is diligent -- even if he has more vices -- will have stronger success than someone who has fewer faults but less dedication to the pursuit of virtue. Two things in particular are helpful to greatly amending ourselves: withdrawing forcefully from the sin to which we are naturally most inclined, and pursuing fervently that good in which we are most lacking. Mark especially those faults you find most frequently in others, and study how to subdue them in yourself.
You will make progress wherever you may be if you see or hear good examples and kindle your spirit to follow them. But if you see* anything blameworthy, be careful that you are not doing the same thing, or if sometime you have done it, quickly learn how to correct yourself. As your eye takes note of* others, so they are also taking note of you. How joyful and refreshing it is to see devoted and enthusiastic brothers in the faith who are self-controlled and sinless. How sad and distressful to see them walking disorderly, not walking the walk to which they are called. How hurtful it is to neglect the purpose of their calling, and to turn their inclinations to things which are not in keeping with their calling.
Be mindful of what you have seized as your purpose, and keep the image of the Crucified before yourself. You might well feel shame as you look on the life of Jesus Christ, because you have not yet made any great effort to conform yourself more to Him, though you have counted yourself as following God's way for a long time. Someone who is religious, who exercises himself seriously and devotedly in the most holy life and passion of our Lord, will find there all things that are useful and necessary. Neither is there any need to seek something better beyond Jesus. Oh! if Jesus crucified would come into our hearts, how quickly and completely we should have been instructed.
A devoted religious person bears all things well, and receives all the commands given. The one who neglects his faith, who is lukewarm, has trouble upon trouble and suffers anguish from all sides: first because he is without inward consolation, and then because he is forbidden to seek that outward consolation. The one who claims a religious life but lives outside of that devotion risks serious ruin. Someone who is seeking that easier, more lenient path is always going to be in distress, because one thing or another will displease him.
Imitation of Christ by Thomas A Kempis, 1.25 (second part).
Translation focused on contemporary English and preservation of rhetorical force and art
* Here, again, it seems likely that the Latin text was mis-transcribed at some points (and again, f for s). Particularly, the online Latin text has "confideraverit" and "confiderat" where a more likely reading would be "consideraverit" and "considerat". I've translated accordingly.
