Here, we see one of the panels Lorenzo Ghiberti created in the fifteenth century for the Baptistery of San Giovanni in Florence.  It depicts Cain and Abel, the Bible's first account of humanity outside of Eden (Genesis 4:1-16).  In the story, the older brother kills the younger.

Many Old Testament texts return to the idea of violence. Warfare is mentioned in every book except Ruth.

In several publications, I wrestle with what to do with the Old Testament's violent texts.
Picture
My latest work on violence in the Old Testament is an article I wrote for the Christian Century after my young daughter asked me why Deuteronomy 20 talks about killing the boys and girls.
Kingdom of Heaven
A question that deeply concerns me is, What convinces people to go to war? In "The Necessity of Permanent Criticism: A Postcolonial Critique of Ridley Scott’s Kingdom of Heaven," Journal of Media and Religion 9 (2010): 129-149, I explore how a Hollywood movie works rhetorically to convince people of war's necessity.
This Strange and Sacred Scripture
This Strange and Sacred Scripture contains a chapter devoted precisely to the question, Why is the Old Testament so violent?
 From Fratricide to Forgiveness
From Fratricide to Forgiveness explores Genesis' teaching on the emotion of anger, which can easily lead to violence.
SBL Forum
In "Teaching the Hebrew Bible amid the Current Human Rights Crisis: The Pedagogical Opportunities Presented by Amos 1:3-2:3," The Society of Biblical Literature Forum 4.1 (2006), I explore the fascinating connections between Amos' oracles against the nations and the Geneva Conventions. 
 Dictionary of Scripture and Ethics
I authored the entry on "Prisoners of War" in the Dictionary of Scripture and Ethics.

Related Topic:

Biblical Ethics
Some images on this page come from Wikimedia Commons. Click the following links to see sources and licensing information: Ghiberti. Operation Iraqi Freedom.