Robert Jones, biblical counseling professor at Southeastern Baptist Theological Seminary, in his new and wise book Pursuing Peace, from a chapter entitled "Battling Bitterness by Grace":
There is nothing uglier than bitterness—that inner anger lodged deep in the heart, sometimes known only to the bitter person (and his all-seeing God). Bitterness is settled anger, the kind that not merely reacts to someone’s offense, but forms a more general and global animosity against the offender himself. Anger responds to an incident: “I’m angry about what you did.” Bitterness goes deeper to form an attitude—a settled stance or posture—against the perpetrator: “I’m bitter at you, because you are an evil person.” The incident becomes almost secondary.
With most hurts we encounter in our imperfect world, especially small ones, we learn to overlook the offense and forgive the offender. But occasionally we experience a major hurt—an offense that cuts deeply or turns our world upside down—that lingers in our minds and tempts us to become bitter. We might store that hurt in our heart, nurture it, and let it grow to the point where we look with hostility at the offender.
What hope do [we] have to escape the sorrow, slavery, and soul impoverishment that resentment brings?
The answer is found in Jesus. Jesus understands. He is with us. He comes to us in our mistreatment and remains with us to help. He understands mistreatment as one who was sinned against severely. He has been there. The Scriptures tell us that he came to save his own people, but they did not receive him (John 1:11; Isa. 53:3).
Jesus was sinned against severely: mocked, taunted, punched, spit upon, abandoned, and crucified. This is the Jesus—the mistreated one—who is with us and who is able to help us handle our resentment and overcome our bitterness.
How? The answer is the gospel message of Jesus Christ.
In Ephesians 4:31, the apostle Paul calls us to “get rid of all bitterness, rage and anger, brawling and slander, along with every form of malice.” The antidote to bitterness? “Be kind and compassionate to one another, forgiving each other, just as in Christ God forgave you” (Eph. 4:32). This verse is the apostle’s strategy to battle the bitterness he warns against in the previous verse. He calls us to have our minds consciously controlled by God’s forgiveness through Jesus’s death on the cross. Grasping the mighty work of our incarnate, crucified, and risen Lord moves us to forgive others.--Robert Jones, Pursuing Peace: A Christian Guide to Handling our Conflicts (Crossway 2012), 138-39
Image credit, and a free downloadable PDF excerpt of the book, here.