What does Proverbs 27:12 mean?

It is wise to try to avoid undue risks. However, the simple-minded person walks headlong into danger. The book of Proverbs defines "wisdom" as a proper understanding of God and His will (Proverbs 1:7; 2:6–7). Part of being "prudent," or "sensible," is to notice risks and take appropriate steps. Those who lack the intelligence—or the self-control—to notice danger more often suffer the consequences of bad decisions (Proverbs 6:5; 13:14; 22:5). This lesson applies both to physical and spiritual threats.

The Devil sets dangerous traps and tries to lure believers into them. An unwise person is prone to walk right into such an ambush. A wise believer heeds the apostle Peter's exhortation: "Be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour. Resist him, firm in your faith" (1 Peter 5:8–9). In Ephesians 6:11 the apostle Paul refers to the schemes of the Devil. He counsels believers to "take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm" (Ephesians 6:13). Although Jesus warned Peter that the Devil planned to aggressively tempt him (Luke 22:31–32), Peter exuded self-confidence. He denied he would ever forsake Jesus (Luke 22:33). Before long, however, Peter fell into the Devil's trap and denied Jesus three times (Luke 22:60–62). It is wise to see danger approaching and avoid it.