I was following a conversation elsewhere about how some Christians insist that everyone really knows that their God is real, it’s just that due to sin, they suppress this knowledge. Everyone is exposed to the illumination of the Holy Spirit, it’s just that those of us who remain skeptical prefer darkness.
Muslims, interestingly, do the same sort of thing, perhaps even more often. It tends to be based on their belief that the created nature (fitra) of every human is such that they are naturally Muslim. Someone departing so far from Islam as to not just associate others with God but to deny all gods must be in the grip of pretty strong immorality — they either lie in stating that they do not believe in God or they do something really drastic to suppress their innate knowledge that there is a God.
And then there are the atheists who claim that everyone is born an atheist, since newborns lack a belief in God and aquire it later through social indoctrination. A rock, presumably, is an atheist, lacking any beliefs whatsoever, and therefore being quite the godless infidel. Many Muslims, mind you, very seriously argue that rocks are Muslim. After all, a Muslim is someone who submits to the laws laid down by God. And a rock has no option but to act according to the laws of physics that were determined by the Great Lawgiver in the Sky.