The authors plot a systematic and logical course to answer this question for their readers. First, the authors establish that God's wrath is not a response to his emotion, but to his intentional action towards a goal. In other words, God's wrath has a purpose or goal to it; it is not capricious. What is that purpose or goal? The goal is to force humanity to come face to face with its own sin and return to faithfulness to God. Building on that insight, Kinghorn and Travis reject the idea that wrath is a primary attribute of God. To prove this they turn the doctrine of the Trinity In the Trinity, what each person (Father, Son, and Holy Spirit) shares is love - not wrath.
The rest of this offering builds upon these two central chapters. Surveying Scriptural numerous references to God's wrath, the authors show how their argument plays out in individual cases of wrath. Sodom and Gomorrah is a case in point. God's wrath that burned again the people of Sodom and Gomorrah was not random or unprovoked. They chose their fate by rejecting God. Abraham pleaded for them, but no one righteous could be found. In His love, God provided a way out, but they rejected this. This leads to the outpouring of God's wrath. Wrath . . . but wrath with a purpose.
While this book is extremely informative and creative in its approach to the question of the purpose and meaning of God's wrath, there are some challenges. The first is their use of personification (or more exact, the over use of personification. Throughout the book, primarily in the first chapter, Kinghorn and Travis makes the argument that we can understand God's wrath and love by understanding our own love and wrath. Personification can be helpful, but it does have limits. These limits are not acknowledged sufficiently by the authors. Another point of weakness in the text is the lack of applying this distinction between love and wrath to modern times. Questions like why do bad things happen to good people or why do innocent people experience God's wrath are not answered.
Despite the challenges, this book is an excellent volume. The authors help the reader understand more fully how God operates and exists in his Trinitarian nature as they explain how wrath is a characteristic of God, but not a primary one. One can imagine future pastors and authors building on these concepts.