There is something in dying that makes us tremble. It is because it may come anytime. And it is one fear that we all have to face and be ready. Preparation for death means preparation to meet God. There is also the fear of people.
People fear people, being embarassed, rejected, confronted, or persecuted, etc.
The natural fears could be wrong fears if it could be a hindrance to you in doing the will of God. We need to put these fears under subjection to the will of God. We all fear man to a certain extent, especially if he hold a position or one of the biggies as they say. But in this text it says the fear of man bringeth a snare. It is because of your fear that you may leave the work undone.