I was raised Catholic, not hardcore Catholic or anything, but Catholic.
So like all religions, I was told that my existence/life, just by virtue of existing, ultimately had a higher purpose/meaning.
As I got older, especially high-school and after, I increasingly became agnostic (An agnostic theist to be specific) and eventually stopped identifying as Christian all-together. And now, these last few years, I've been transitioning from that to full-on atheism.
I'm not 100% there though, and I'm not sure I ever will be. Because no matter how hard I try, there's this part of me that simply can't/won't fully accept the possibility that my existence/life really and truly is pointless, even though I know that's the most likely scenario.
It's like being given the softest, warmest blanket you've ever felt in your life, the idea that you're here for a reason and that after it's over you'll get to see and be with all the people you've loved and lost in your life forever...
...and then having it ripped from you and thrown outside into a blizzard, that it was all a lie.
And no matter what I've been told by others to try and replace that blanket, whether it's been stuff like "You give your life meaning." or "Just have fun while you're here.", none of it has actually made me feel better, no matter how hard I try.
It's like some Lovecraft shit: I've seen the horrible truth, but my mind simply cannot fully comprehend/accept it, and thus I'm slowly going mad from the revelation.
If I had been raised atheist from birth, I think I'd be handling all this better. It's the fact that I once believed existence/life had an ultimate meaning, and had that taken away from me, that's creating this conflict.
If I had never been given that blanket and known it's warmth, and was instead just born into the blizzard, I'd be better off right now.
I really think that feeling of meaninglessness is just the alienation of being divorced from our ancient tribal existence. That lifestyle must have offered a deep sense of belonging and purpose that modern life simply cannot reproduce. I doubt hunter gatherers worry so much about meaninglessness. They're probably quite fulfilled by their ramblings through the wilderness with their friends and loved ones. As for religion, I think religious people's beliefs are simply simulating that feeling, both in the earthly community of the faithful and to a larger extent in heaven. Atheists are faced with a somewhat starker view of our alienation. The good news is that your brain is still fully capable of producing those feelings of fulfillment under the right circumstances. I just don't know how to find them in an incredibly alienated late capitalist society like ours.
A life of unalienated labor sounds incredibly fulfilling, I think that Marx guy was on to something.