Tetra
I very much agree with you that a major concern is that life is meaningless. The almost cliched response of reckless abandon that some have after losing their religion supports that it was a central concern for themselves anyway. I think the degree of dread this particular concern causes varies.
I wonder if religion came about not only to address all the fears mentioned by Narkissos, but also to attenuate the discrepancy between the way the human mind is wired and apparent reality. Looking for patterns and causes in an often random universe, the dissonance between our sense of justice and the rather amoral natural (as well as artificial) world we live in, etc.
I think the Epicurians could be "godless" because they consciously dealt with these fears and realizations and just accepted them. Just like you said in your own post "stare" right into them.