What does the Bible say about vengeance?

The concept of vengeance in the Bible underscores God's divine justice, which necessitates retribution for sin. In Judges 15, Samson expresses his desire for vengeance after the unjust killing of his wife by the Philistines. This act symbolizes a deeper truth about God's justice; He must avenge His elect—those who cry out to Him for justice. As Luke 18:7 states, 'Shall not God avenge his own elect, which cry day and night unto him?' Vengeance, therefore, is not merely personal but part of God's righteous character, fulfilling the law that demands satisfaction for sin.