I’m sure the ancient Greeks thought that their gods were real also, as did the ancient Egyptians and many other ancient and current cultures.
I personally believe in the Flying Spaghetti Monster, Ramen! But of course I have no proof it exists.
Check it out here:
I do not agree. Some likely did but not many.
I believe that literal belief in God is a fairly recent phenomenon ushered in by Protestantism.
I cannot believe that the ancients, who were quite materialistic out of necessity, were not stupid enough to believe that snakes and asses could talk human.
Jews also had so many names for God over time that they also had no fear of switching Gods.
One does not switch Gods if one believes in them as real.
Also, Rome had a nameless God for those who did not want to bother with the known or named ones.