In contrast to the sins of resentment listed in Ephesians 4:31, Paul explains that Christians are to grow more and more in kindness, tenderheartedness and forgiveness. These virtues are polar opposites to the sinful traits of bitterness, anger, wrath, clamor, slander and malice. Our motivation to be kind, tenderhearted and forgiving is because God has been kind, compassionate and forgiving of us.