Be kind and tenderhearted to one another, forgiving each other just as in Christ God forgave you.
32. And be ye kind one to another. With bitterness he contrasts kindness, or gentleness of countenance, language, and manners. And as this virtue will never reign in us, unless attended by compassion, (ουμπάθεια,) he recommends to us to be tender-hearted This will lead us not only to sympathize with the distresses of our brethren, as if they were our own, but to cultivate that...
The apostle having gone through his exhortation to mutual love, unity, and concord, in the foregoing verses, there follows in these an exhortation to Christian purity and holiness of heart and life, and that both more general (Eph 4:17-24) and in several particular instances, Eph 4:25-32.
Commenting on Ephesians 4:17-32
Verse 32. And be ye kind one to another. Benignant, mild, courteous, polite--χρηστοι. . Christianity produces true courteousness, or politeness. It does not make one rough, crabbed, sour; nor does it dispose its followers to violate the proper rules of social intercourse. The secret of true politeness is benevolence, or a desire to make others happy; and a Christian should be the most polite of men.