For we are accused of being Christians, and to hate what is excellent (Chrestian) is unjust.
Acts of Xanthippe, Polyxena, and Rebecca 9 (3rd or 4th cent):--Paul said [to Xanthippe], No, daughter, but the devil, who hates the servants of God, sows wickedness in the hearts of his own servants, to oppose those that labour for Christ in preaching, for his wickedness has extended to the apostles and ever, to the Lord himself. Therefore it is fitting to approach the unbelievers gently and kindly!
St. John Chrysostom (c.347-407), Homily 33:--But Paul doth not stop here, but adds also the other high achievements of love, saying, "is kind." For since there are some who practise their long-suffering with a view not to their own self-denial, but to the punishment of those who have provoked them, to make them burst with wrath; he saith that neither hath charity this defect. Wherefore also he added, "is kind." For not at all with a view to light up the fire, in those who are inflamed by anger, do they deal more gently with them, but in order to appease and extinguish it: and not only by enduring nobly, but also by soothing and comforting, do they cure the sore and heal the wound of passion.
John Cassian (c.360-435), The Twelve Books on the Institutes of the Cœnobia, and the Remedies for the Eight Principal Faults, Book X:--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 (Matt. 5:45-35), 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.