Throughout the bible we are encouraged to fear the Lord . ( not be afraid off but revere / be in awe)
Proverbs 9:10 says it's the beginning of wisdom - foundation / starting point
Nadab & Abihu (Leviticus 10) brought a profane offering before God and paid the ultimate price for being irreverent .They had authority to present the offering and went through the process but They had treated what was sacred as common and what was holy as ordinary.
We sing/ cry out to God to show us His glory etc but
God will not reveal His presence where He is not held with the upmost of respect . We might say or do 'the right things' but God examines the heart.
When we fear God we venerate Him ( revere,respect,honour,stand in awe of)We find what is important to Him becomes important to us -we love what He loves and hate what He hates ( things we once tolerated we don’t
anymore – if it goes against the word- may be accepted in society- everyone is
doing it – We’ll obey Him instantly even though it doesn’t make sense or we know its going to hurt .
Psalm 25:14- The secret of the Lord is with those who fear Him,
He wants to reveal secrets to us etc - give us strategies