We may not live in constant fear of death, especially when we are in our comfortable study, tapping at the keyboard, but let that oncoming semi veer uncomfortably into our lane and BINGO it’s baaack! We unconsciously respond with a life-saving swerve.
It’s not going away. It’s built in. If it weren’t, we wouldn’t live past six years of age. All we can do is develop mental practices that keep it from eroding our daily peace of mind. When we need it, it will still be there.
Atheism is a good first step in such a practice. Mindfulness is another. Full spiritual liberation is the most complete solution. I suspect this is really what the esoteric practitioners of ancient religions were actually pursuing; not the woo-slinging that their followers have taken up.