The first requirement of growing in fear is having an undivided heart
Give me an undivided heart, that I may fear your name - Psalms 86:11
It dentoes singleness of purpose, aim, and affections
No one can have two masters
Second requirement is regular, consistent exposure of our minds and hearts to His Word:
Saul fell down in fear before Christ
"He asked Who are you, Lord?" and "What shall I do, Lord? - Acts 22:8,10