What causes violence?

Genesis 37:3-4, 18, 20Jacob loved Joseph more than any of his other children because Joseph had been born to him in his old age. So one day Jacob had a special gift made for Joseph—a beautiful robe. But his brothers hated Joseph because their father loved him more than the rest of them. They couldn’t say a kind word to him. . . . When Joseph’s brothers saw him coming, . . . they made plans to kill him. . . . “Come on, let’s kill him and throw him into one of these cisterns. We can tell our father, ‘A wild animal has eaten him.’ Then we’ll see what becomes of his dreams!”

Envy, anger, and resentment, if left unresolved, spreads like wildfire and leads to actions of violence and even murder.

Mark 7:20-23Then he [Jesus] added, “It is what comes from inside that defiles you. For from within, out of a person’s heart, come evil thoughts, sexual immorality, theft, murder, adultery, greed, wickedness, deceit, lustful desires, envy, slander, pride, and foolishness. All these vile things come from within; they are what defile you.”

The human capacity for violence is an aspect of our fallen nature.