The audience at the time of revelation of Quran were mainly theists and polytheists. However the Quran did address the questions put forth by present day atheists.
Hmmm...strange....as a poorly practicing Muslim my tongue goes on auto-pilot and says, "SubhanAllah"
Image Source : CNN
Lawrence Krauss,""I can’t prove that God doesn’t exist," , but I’d much rather live in a universe without one."