Atheism Is Very Ancient, Study Finds

I can believe that, but from what I know of Rome under the pagans they were much the same way.  They didn't care which gods you believed in as long as you believed in some.  Atheism would have been an uncontrollable danger if it had become fashionable (like it is today).

There was a Roman admiral named Claudius Pulcher in the First Carthaginian War who went to sea with priests and chickens aboard his flagship, and the priests were supposed to interpret the future by how the chickens pecked at their food.  At sea the chickens refused to eat, so in disgust Pulcher threw them overboard.  In the next battle his fleet was soundly beaten by the Carthaginian fleet, and in shame he committed suicide for the defeat brought about by his sacrilege of tossing the chickens over the side.  I post this as an example of how important religion was in Roman times.  Would an atheist ever have been allowed to hold such an important command in the first place?  I doubt it.

   I suspect it is human nature that if anyone says up, someone else is going to say down.  If anyone says warm, someone else is going to say cool.  If someone says right, someone else is going to say left, and so  on.

The first example I know of a Christian Atheist may have been William Blake. He created his own mythology but borrowed heavily from Christianity, essentially portraying the OT God as the real adversary/Satan, while Jesus was the real God because he was "the God within man" and "God as artist/storyteller." He was also into the whole notion of religions/mythologies essentially being expressions of human psychology, long before the likes of Jung and Peterson were around writing/talking about the idea. 

Perhaps the robin thing disproves the existence of God in the minds of some, but not all.  As you should know by now, there's quite a lot accepted by mainstream Christianity that I don't readily swing into.