Fear should be that we will not be able to make the correction called “equivalence of form,” which is called “because He is great and ruling,” where one’s only aim is to bestow. Also, the created beings should have the same intention: to bestow.
Conversely, the rest of the fears, whether of punishments in this world or punishments in the next world, are called “reception” and not “bestowal.” The purpose of our work is that through the Torah and Mitzvot [commandments], we will achieve bestowal. This is the meaning of “God has made it so that He would be feared.”
The question is why does He need us to have fear. The idea is that through this fear we will acquire the vessels of bestowal, called “equivalence of form,” and then we can complete the purpose of creation.