Does one need a specific explanation for the claim that one doesn't believe religious claims? That's all atheism is, by the way; a lack of acceptance of religious dogma, nothing more.
As concerns materialism, I shan't be speaking for everyone, but I doubt you'll find a strict materialist anywhere around here; most of us are smart enough to realize that we don't know everything yet, and thus won't directly discount the possibility that something more/as yet unknown about the material world exists. However, the time to properly believe that such a thing is out there is the time one has evidence that it does.
We aren't unjustified in believing in the material world because... well, it's here. We're... we're in it.
As concerns materialism, I shan't be speaking for everyone, but I doubt you'll find a strict materialist anywhere around here; most of us are smart enough to realize that we don't know everything yet, and thus won't directly discount the possibility that something more/as yet unknown about the material world exists. However, the time to properly believe that such a thing is out there is the time one has evidence that it does.
We aren't unjustified in believing in the material world because... well, it's here. We're... we're in it.

"YOU take the hard look in the mirror. You are everything that is wrong with this world. The only thing important to you, is you." - ronedee
Want to see more of my writing? Check out my (safe for work!) site, Unprotected Sects!
Want to see more of my writing? Check out my (safe for work!) site, Unprotected Sects!