(Posted some of this in a PM -- taking the plunge to go public. While I find it relatively easy to be out as a gay man, coming out as an agnostic is much much more frightening.)
Here's my take, as a non-believer.
If you really don't believe in God...if the world just happened, and there's no reason it needed to happen, no cosmic hand pulling the strings...everything becomes much more miraclous. Without worrying about why a perfect being created an imperfect world, you can really be in awe of the world as it is. Isn't it amazing that some particles of matter, four fundamental forces, lots of dark matter and maybe dark energy, got together, and now I'm sipping my coffee typing this?
I don't know if people would agree with me, but it makes everything seem much more powerful and special. I didn't exist before I was born-I won't exist after I die--I'm a singular, unrepeatable event in space and time. I'm not part of a great plan, but I can make my own plans. I have a heart, intelligence, love, and they're not just pale reflections of some heavenly force...I think we're all there is, and we're beautiful. And there's no reason at all that we had to be here, so I celebrate the fact that we are.
And even if I'm in pain, or feeling alone, I can still step back and think about how strange and wonderful it is that a bunch of atoms can be alive and feel alone.