I remember in Christian fundamentalist circles after 9/11 remarking they might not be ready to die for their faiths like terrorists are. Not the best introspection to be doing, I don’t think.
Obviously, even among the truly devout, humans have innate urges to stay alive. Fear of death is often one of the last steps in any faith. After life and fear of death is also one of the bigger preoccupations with many faiths. It’s the big unknown.
Everyone has to die and no one is ever truly ready.