3 When I reflect on these good things, these gifts of God in you, my heart, amid the many storms by which it is agitated through evils elsewhere, is wont to find perfect rest. “You did run well; who did hinder you, that you should not obey the truth? This persuasion comes not of Him that calls you.” “A little leaven”— I am unwilling to complete the sentence, for I rather desire, entreat, and exhort that the leaven itself be transformed into something better, lest it change the whole lump for the worse, as it has already almost done.
If, therefore, you have begun to put forth again the buddings of a sound discernment as to your duty, pray that you enter not into temptation, nor fall again into strifes, emulations, animosities, divisions, evil speaking, seditions, whisperings. For we have not laboured as we have done in planting and watering the garden of the Lord among you, that we may reap these thorns from you. If, however, your weakness be still disturbed by turbulence, pray that you may be delivered from this temptation. As for the troublers of your peace, if such there be still among you, they shall, unless they amend their conduct, bear their judgment, whoever they be.
Source: Letters (New Advent)