Believers can strengthen the hands of the wicked by approving of their works or remaining silent concerning their God’s view of those wicked works.
Sin causes a man's strength to fail. On the contrary, "the way of the LORD is strength to the upright." Man's choice to sin will eradicate his strength.
Man is not promised an endless supply of strength for him to store up. Rather, God promises to provide the necessary grace and strength for the present trials.
Vengeance is not always executed in a swift fashion (Ecclesiastes 8:11). In fact, believers often grow weary because the wicked seem to prosper in spite of their evil deeds. Yet, the Lord will execute vengeance in His time. The Bible speaks often of “the day of vengeance” to come. This day is very likely a thousand year period (2 Peter 3:8) which will begin shortly before the second coming of the Lord and will end at the great white throne judgment following the end of the millennial kingdom. It will be a time when the Lord will refuse to spare the wicked (Proverbs 6:34) but will set things right for the Jewish people (Isaiah 34:8; Isaiah 61:2; Isaiah 63:4).
A simplistic view of vengeance involves the retribution of an evil deed. The first (Genesis 4:15) and last (Jude 7) mention of the word vengeance substantiates this definition. The Bible uses words like recompence (Deuteronomy 32:35), reward (Deuteronomy 32:41), punishments (Psalm 149:7), avenge (Jeremiah 46:10), revenge (Ezekiel 25:15), and repay (Romans 12:19) as descriptive words for vengeance. With this in mind, it is clear that vengeance is the just punishment as a consequence upon those who violate the laws of God. It is not the dispensing of wrath without cause but is specific punishment exacted for specific crimes committed.
