The word ‘fear’ as used in the Bible is a perfect example of how words have changed over time and now have a slightly different meaning.
The word ‘fear’ as in ‘we should fear God’ does not mean that we should be scared of him, as the modern meaning of the word would suggest. Instead, the word ‘fear’ means ‘a healthy respect for’, or to ‘stand in awe of’ him - or, even more accurately, a mixture of the two.