Definition and Nature
God's vengeance refers to the divine retribution and justice executed by God in response to sin and disobedience. It is an expression of His holiness and righteousness, ensuring that justice is served according to His perfect will. Unlike human vengeance, which can be tainted by sin and personal vendettas, God's vengeance is pure, just, and aimed at restoring divine order.

Biblical Foundation
The concept of God's vengeance is rooted deeply in Scripture, where it is portrayed as a necessary aspect of His character. In Deuteronomy 32:35, God declares, "Vengeance is Mine; I will repay." This statement underscores the principle that vengeance belongs to God alone, and He will execute it in His perfect timing.

Old Testament Examples
Throughout the Old Testament, God's vengeance is depicted in various narratives and prophetic declarations. In the book of Nahum, God's vengeance is directed against Nineveh, the capital of Assyria, for its wickedness and oppression. Nahum 1:2 states, "The LORD is a jealous and avenging God; the LORD is avenging and full of wrath. The LORD takes vengeance on His foes and reserves wrath for His enemies."

Another significant example is found in the account of Sodom and Gomorrah, where God's vengeance is executed through the destruction of these cities due to their grievous sins (Genesis 19:24-25). This act serves as a warning of the consequences of persistent unrighteousness.

New Testament Perspective
In the New Testament, the theme of God's vengeance continues, emphasizing the ultimate judgment that will occur at the end of the age. Romans 12:19 advises believers, "Do not avenge yourselves, beloved, but leave room for God’s wrath. For it is written: 'Vengeance is Mine; I will repay, says the Lord.'" This passage encourages Christians to trust in God's justice rather than seeking personal revenge.

The book of Revelation vividly portrays God's final vengeance against evil. Revelation 19:2 proclaims, "For His judgments are true and just. He has judged the great prostitute who corrupted the earth with her immorality, and He has avenged the blood of His servants shed by her hand."

Purpose and Implications
God's vengeance serves multiple purposes. It acts as a deterrent against sin, a means of purifying His people, and a demonstration of His sovereignty over creation. It also reassures believers that justice will ultimately prevail, even when it seems delayed.

The knowledge of God's vengeance should lead to a reverent fear of the Lord and a commitment to live righteously. It also calls believers to trust in God's timing and justice, refraining from taking matters into their own hands.

Mercy and Vengeance
While God's vengeance is a reality, it is balanced by His mercy and grace. God desires repentance and offers forgiveness to those who turn from their wicked ways. Ezekiel 33:11 expresses this heart of God: "As surely as I live, declares the Lord GOD, I take no pleasure in the death of the wicked, but rather that the wicked should turn from their ways and live."

Conclusion
The doctrine of God's vengeance is a sobering reminder of His holiness and justice. It calls for a response of faith, repentance, and trust in His righteous judgment.