I disagree, why will he eventually grow out of his fear of death? I think if the majority of the worlds population didn't believe in a god, afterlife, mother nature or something like the spirit world then we would have millions of people with a active fear of death.

The only people that truly don't fear real death are atheists that have made peace with that fact.

I am a atheist that has not out grown a fear of death, but I can't relate to anyone I know because they all say the same as you, "you will eventually out grow that fear", then I ask what if I am right and when we die we are forever gone and there is no afterlife? They say "Well that is unlikely, there is something else out there" So everyone I know doesn't fear death, because they think they will never truly die anyway.

Like I said, the only people on earth that really do not fear death are a small amount of the atheist population that have come to accept death as inevitable. But what I think is that if all of humanity was atheist, we would be pouring billions in immortality research.