Atheists should not have a fear of death, it is a routine thing that happens to living beings. We are none other than 'star material', Brahman, which constitutes the universe and all things contained in it, which perhaps is not bounded by even existence and non-existence.
.
The fear stems from identification with the temporal.
It has nothing to do with atheism or theism, indeed theists should fear death less for they think they know what happens beyond death.
It is the identification which must be overcome if suffering is to cease. It is mind which creates the difficulty, in its need to be something, it realizes all it incorporates towards this will cease eventually. It becomes panicked in this realization, yet what we actually are simply watches this. We can choose whether to go into the panic, if we don't then it is clear we are beyond the mind, witnessing happens and the mind ceases to be given energy.
Then though, what are we? What is seen, which I have called the witness, is beyond all existential phenomenon, yet is not non-existent. It is simply beyond all categories, for the very categorizing mechanism is another mental process appearing within this space, this Brahman or void, this Sunyata or emptiness. Like an empty room, it is merely potentiality itself, and the force used to decorate, that which creates what we call life, is love itself.
This is why all the scriptures say God is love, the energy which creates om is love, but without it, still there is Brahman or sunyata, what we call darkness.