Answer
The Bible has a great deal to say about revenge. Both the Hebrew and Greek words translated “vengeance,” “revenge,” and “avenge” have as their root meaning the idea of punishment. This is crucial in understanding why God reserves for Himself the right to avenge.
The key verse regarding this truth is found in the Old Testament and quoted twice in the New Testament. God said, “It is mine to avenge; I will repay. In due time their foot will slip; their day of disaster is near and their doom rushes upon them” (Deuteronomy 32:35; Romans 12:19; Hebrews 10:30). In Deuteronomy, God is speaking of the stiff-necked, rebellious, idolatrous Israelites who rejected Him and incurred His wrath with their wickedness. He promised to avenge Himself upon them in His own timing and according to His own perfect and pure motives. The two New Testament passages concern the behavior of the Christian, who is not to usurp God’s authority. Rather, we are to allow Him to judge rightly and pour out His divine retribution against His enemies as He sees fit.
Unlike us, God never takes vengeance from impure motives. His vengeance is for the purpose of punishing those who have offended and rejected Him. We can, however, pray for God to avenge Himself in perfection and holiness against His enemies and to avenge those who are oppressed by evil. In Psalm 94:1, the psalmist prays for God to avenge the righteous, not out of a sense of uncontrolled vindictiveness, but out of just retribution from the eternal Judge whose judgments are perfect. Even when the innocent suffer and the wicked appear to prosper, it is for God alone to punish. “The LORD is a jealous and avenging God; the LORD takes vengeance and is filled with wrath. The LORD takes vengeance on his foes and maintains his wrath against his enemies” (Nahum 1:2).
There are only two times in the Bible when God gives men permission to avenge in His name. First, after the Midianites committed hideous, violent acts against the Israelites, the cup of God’s wrath against the Midianites was full, and He commanded Moses to lead the people in a holy war against them. “The LORD said to Moses, ‘Take vengeance on the Midianites for the Israelites. After that, you will be gathered to your people’" (Numbers 31:1-2). Here, again, Moses did not act on his own; he was merely an instrument to carry out God’s perfect plan under His guidance and instruction. Second, Christians are to be in submission to the rulers God has set over us because they are His instruments for “vengeance on evildoers” (1 Peter 2:13-14). As in Moses’ case, these rulers are not to act on their own, but are to carry out God’s will for the punishment of the wicked.
It is tempting to try to take on the role of God and seek to punish those who we feel deserve it. But because we are sinful creatures, it is impossible for us to take revenge with pure motives. This is why the Mosaic Law contains the command “Do not seek revenge or bear a grudge against one of your people, but love your neighbor as yourself. I am the LORD” (Leviticus. 19:18). Even David, a “man after God’s own heart” (1 Samuel 13:14), refused to take revenge on Saul, even though David was the innocent party being wronged. David submitted to God’s command to forego vengeance and trust in Him: “May the LORD judge between you and me. And may the LORD avenge the wrongs you have done to me, but my hand will not touch you (1 Samuel 24:12).
As Christians, we are to follow the Lord Jesus’ command to “love your enemies and pray for those who persecute you” (Matthew 5:44), leaving the vengeance to God.