Just as patience will take anything from others, kindness will give anything to others, even to its enemies. Being kind is the counterpart of being patient. to be kind (chresteuomai) means to be useful, serving, and gracious. It is active goodwill. It not only feel generous, it is generous. It not only desires others' welfare, but works for it. When Jesus commanded His disciples, including us, to love their enemies, He did not simply mean to feel kindly about them but to be kind to them. "If anyone wants to sue you, and take your shirt, let him have your coat also. And whoever shall force you to go one mile, go with him two" (Matt.5:40-41). The hard environment of an evil world gives love almost unlimited opportunity to exercise that short of kindness.
Again, God is the supreme model. "Do you think lightly of the riches of His kindness and forbearance and patience, not knowing that the kindness of God leads you to repentance?" (Rom.2:4), Paul reminds us. To Titus he wrote, "but when the kindness of God our Savior and His love for mankind appeared. He saved us, on the basis of deeds which we have done in righteousness, but according to His mercy, by washing of regeneration and renewing by the Holy Spirit, whom He poured out upon us richly through Jesus Christ our Savior" (Titus 3:4-6).
Peter tells us that we should "long for the pure milk of the world" and thereby "grow in respect to salvation," because we "have tasted the kindness of the Lord" (1 Pet. 2:2-3).
To His disciples Jesus says, "for My yoke is easy, and My load is light" (Matt.11:30). The word He used for "easy" is the one translated kind in 1 Cor.13:4. In His love for those who belong to Him, Jesus makes His yoke "kind," or mild. He makes sure that what His people are called to bear for Him is bearable (see 1 Cor. 10:13). The first test of Christian kindness, and the rest of every aspect of love, is the home. The Christian husband who acts like a Christian is kind to his wife and children. Christian brothers and sisters are kind to each other and to their parents. They have more than kind feelings toward each other; they do kind, helpful things for each other -- to the point of loving self-sacrifice, when necessary. I must be able to self-sacrifice my wants and desires to truly love someone the way Jesus did.
For the Corinthians though, kindness meant giving up their selfish, jealous, spiteful, and proud attitudes and adopting the spirit of loving-kindness. Among other things, it would allow their spiritual gifts to be truly effectively ministered in the Spirit, rather than superficially and unproductively counterfeited in the flesh.