Is the fear of irrational fears rational?

[Aegon]

Fear of God seems pretty irrational 

But if a person is convinced that there is a God, does that make their fear rational? If I truly thought there was an entity that controlled whether I would burn in Hell or not, it'd certainly be rational to fear that entity. The belief in the entity itself is irrational, but if we accept the premise of God, then a fear of God under that premise is rational.