Sometimes, church members who should be striving to usefully build up the body of Christ find themselves useless for the task. They fail to contribute to the overall health of the body, even though they may faithfully attend, faithfully give and faithfully involve themselves in ministries. What makes them ultimately useless and in fact destructive to the Body is a disposition of bitterness. Paul addresses this in the closing verses of Ephesians 4.
In v. 31 he identifies the spirit of the useless church member—those with a spirit of bitter and angry unforgiveness. In v. 32, he identifies the spirit of the useful church member—those with a spirit of kind and tenderhearted forgiveness. Simply, the apostle offers a twofold exhortation: (1) stop being bitter (v. 31); and (2) start being kind (v. 32).