People may have fear of (losing, getting, being, not being,...) something or may fear for the fear of such. Fear of Hell would/could make people 'good'. Fear of Danger may make people more careful and become more conscious of causes and effects in what they do...

When we understand fear for what it is, when it arises, when it takes control (of our emotions and actions), when it subsides, what it leaves behind (on our body and in our mind)... we would see another dhamma (another anatta).

Fear can be useful and harmful - sometimes at the same time! ;-)

Fear not what our imagination can do but we should not 'believe' in our thought-up fear.