Wow, I wondered off some atheist blogs and boy, are they insulting and impolite. They really do foam in the mouth with animosity towards theists in general and Christians in particular. The latter is the usual punching bag and target of verbal insults and boy, do they make an art out of it.
I was an atheist during my university years, in fact that is why my minor was Philosophy.
If the Bible is the Word of God then it is God speaking there, so to know what God thinks of atheists, see Psalm 14:1.
God calls them "fools". Now that is a nice term, the Bible is being nice, but I think the translation of that word is found here.
Now, pleases do not get mad at me, I did not write the Bible.