As an instinct, fear can be a good thing, keeping us out of harm’s way. It helps us avoid things like, well, provoking gangsters and thugs – fearing what they might do to us encourages a basic kind of wisdom.
Christ reasons, by way of contrast, that there’s only one to be afraid of: God. (Lk 12:4-5) God is capable of inflicting so much damage and harm, truly an infinite amount of pain and suffering, that all other fears should pale in comparison; the very thought of offending Him should move us to trembling (Php 2:12), even as we’re rejoicing in Him. (Ps 2:11)
Many prefer to focus on respect or reverence rather than fear, perhaps to encourage us to be more comfortable with God. But that’s like telling us to relax when our clothes might be catching fire.
The potential danger we’re all in with God is incredibly real, and there’s no point in playing it down: He’s a consuming fire (He 12:29), and most of us are chaff. (Mt 3:12) Even for the best of us, it’s a fearful thing to fall into His hands (He 10:31), and all of us will: evading Him isn’t an option. The slightest uncertainty here should terrify us. (2Co 5:11)
Firstly, a healthy fear of God keeps us from presumptuous sin, from carelessly offending Him (Pr 16:6), and that’s just plain smart – like not poking a gorilla in the eye, even if he seems friendly.
Godly fear also motivates us to ensure our election (2Pe 1:10), striving to enter the narrow gate (Lk 13:24) and pass fully into His rest. (He 4:11) In light of the second death, living for even a moment without absolute assurance of eternal life is unthinkable. (2Co 13:5)
Fear in itself, rational fear of any kind, would never encourage us to run or hide from God: thinking we can avoid omnipresence is like trying to escape from space and time itself; the thought is unintelligent at best. Only an insane dislike, a relentless distaste for the divine, would seek to escape from One who inhabits eternity.
Perhaps this is partly why “the fear of JEHOVAH is the beginning of wisdom.” (Pr 9:10) Try to fathom a soul with any sense of propriety or understanding that willfully chooses to neglect or offend omnipotence. How can anyone with a grain of sense not “kiss the Son, lest He be angry, and ye perish from the way when His wrath is kindled but a little?” (Ps 2:12)
A lack of reverence for God, any willingness to sin against Him deliberately, on purpose, not choosing to fear Him in every healthy sense of the word (Pr 1:29), is essentially a failure to grasp the fundamental nature of God; it’s either rank unbelief in who God says He is, or exceedingly irrational.
The fear of God is our friend (Ps 19:9a): choose it (Pr 1:29) and be wise. Learn to fear Him rightly (Ps 34:11); God’s children don’t take Him lightly, casually; we fear Him unto joy. All else is unbelief, enmity, no matter how we slice it.