The fear of the LORD is the beginning of knowledge;
fools despise wisdom and instruction. (Proverbs 1:7)

I am not a Hebrew scholar so I can’t tell you much about the meaning of the Hebrew word used for fear, but this phrase from Proverbs (found elsewhere, too) has always made sense to me.

Fear does imply being afraid. If you stop to think about what a holy and perfect and righteous God is like, and then compare it to your own life, then you ought to be afraid. Nothing you do can live up to that. Thanks be to Jesus Christ, because He has done what you cannot. Praise God!

Fear does imply reverence not necessarily motivated by being afraid. A respect, perhaps. God, who created all things, is certainly worthy of our respect.

This fear also implies the kind of fear of disappointment. If you think of God as a father, then you should want to please Him and not disappoint Him.

Fear God and you have the beginning of wisdom and knowledge.