This is a tough chapter. It relates the account of Jacob's daughter being raped and her brothers, Simeon and Levi, exacting revenge by deceiving the men of Shechem into being circumcised and then attacking and slaughtering them all while they were incapacitated. They then captured the wives and children and stole all their belongings.
It contains no mention of God — not while Jacob was waiting for his sons to return from the fields, not when Hamor and his son, Shechem, tried to negotiate to have her as his wife, and not when Dinah's brothers considered what to do about it.
Clearly, Shechem's rape of Dinah was wrong (and if you've watched or read The Red Tent, it doesn't jive with the biblical account. This wasn't a romance ala Romeo and Juliet where they were in love, but their families couldn't get along. This was rape.)
But were the brothers any better in deceiving (there's that theme of deception rearing its head again) and then slaughtering the whole city for the crime of one man?
When we don't consult God, we get a warped notion of justice. Like Lamech (Genesis 4), we think, "If Cain is avenged seven times, then Lamech seventy-seven times." But Jesus says when asked how many times we must forgive, “I tell you, not seven times, but seventy-seven times." Seven is often identified as a number representing completeness in the Bible and seventy-seven times represents infinity. We are to be about forgiveness and entrust vengeance to God.
Our revenge is marred by our own sin nature, but God is just.
Our revenge creates hatred in our hearts, but trusting God allows our hearts to heal.
Our revenge causes us to be no better than the ones we believe are deserving of our wrath, but God blesses us when we demonstrate mercy.