John Cassian, The Institutes X.15: How kindness should be shown even to the idle and careless

Nevertheless, like a far-sighted and careful physician, he is not only anxious to heal the wounds of the sick, but gives suitable directions as well to the whole, that their health may be preserved continually, and says: “But be not ye weary in well doing:” ye who following us, i.e., our ways, copy the example given to you by imitating us in work, and do not follow their sloth and laziness: “Do not be weary in well doing;” i.e., do you likewise show kindness towards them if by chance they have failed to observe what we said. As then he was severe with those who were weak, for fear lest being enervated by laziness they might yield to restlessness and inquisitiveness, so he admonishes those who are in good health neither to restrain that kindness which the Lord’s command bids us show to the good and evil, even if some bad men will not turn to sound doctrine; nor to desist from doing good and encouraging them both by words of consolation and by rebuke as well as by ordinary kindness and civility.