In my experience as a Christian orthodox, the fear of the **** is the idea that a higher being or a father-like figure is always watching over you which should stop you from doing sin. The idea is that because you feel like someone is always watching you will feel too ashamed or guilty to do something "sinful" which I personally don't agree with because a person should be inherently good, not because religion told them to be good. But that's just my personal experience, hope this helped!