What does "the fear of the LORD" entail? Another proverb, Proverbs 9:10, helps us to understand: "The fear of the LORD is the beginning of wisdom, and the knowledge of the Holy One is understanding." While Proverbs 8:13 defines what the fear of the Lord is, Proverbs 9:10 shows what it produces. Understanding the effect of the fear of the Lord will help us to understand the cause.
This verse uses a Hebraism in which the two clauses are written in parallel. The "fear of the LORD" in the first clause is linked to "knowledge of the Holy One" in the second, while the "beginning of wisdom" corresponds to "understanding." Most translations hide the fact that the Hebrew word rendered as "Holy One" is actually plural. It refers to both holy, divine Beings—the Father and the Son. We can more fully grasp this in conjunction with John 17:3, where Jesus says that knowing the Father and the Son—having personal, intimate knowledge of the Holy Ones—is eternal life.
In tying these things together, we see that the wisdom and understanding in Proverbs 9:10 are not abstract concepts but are related to eternal life. They are foundational to being able to live eternally. The reverential awe and respect—fear—of God is what produces wisdom in making sound choices, in having good judgment, in understanding cause and effect. The fear of God makes for a good life—not just for the self, but also for everyone for all time.
James describes such "wisdom from above" as "first pure, then peaceable, gentle, willing to yield, full of mercy and good fruits, without partiality and without hypocrisy" (James 3:17). These elements produce a good life, a life of spiritual wisdom. All of them are opposites of evil, of causing harm. Godly fear causes a man to evaluate properly and to arrive at the correct conclusion about what he should or should not do. Ultimately, the fear of the Lord teaches us to live eternally—to live with the skill that the Father and the Son have in living.
Returning to Proverbs 8:13, we can see how hating evil fits into this. When we are vehemently opposed to all that does harm to life and liveliness, and our lives reflect this, we are beginning to live as God does. However, we have to put wisdom in the context of eternity. What may seem "harmless" in the short term may bear evil fruit in the long term. Unless we are able—and willing—to look as far forward as possible to see the outcome, we may not be able to see the harm.
Because of man's fickle and shortsighted nature, God has explicitly defined what is good and evil in His law, and the evil that is defined is sin. It may not be immediately obvious to mankind that burning incense to the Queen of Heaven causes harm because mankind is shortsighted enough not to realize that he is paying homage to a worthless substitute of the true Creator, the One who gives life. Thus, God spells out that we can have no other gods (Exodus 20:3).
Mankind may not see the harm in a "little white lie" (Exodus 20:16), but the One "who inhabits eternity" knows that truth and life are inextricably linked. When falsehood enters in, so do defilement and ultimately death.
Humanity may not be aware of the harm caused by coveting (Exodus 20:17), but the One "who knows the end from the beginning" and who created the human intellect and human heart, knows that sin begins in the heart. The best way to stop sin at its source is to help mankind to guard his heart, before any sin can be produced.