The people who wrote the Old and New Testaments and the Koran all thought that God was a being who looked like a man, who lived in the sky and watched us, and so did almost all practicing Jews, Christians and Muslims until a couple of centuries ago. Those Christians and Muslims, plus those of the practicing Jews who believed in life after death (never a unanimous belief among Jews) believed that Heaven was up in the sky where God lived, and that Hell was deep underground. They believed that angels and demons, who looked somewhat like people except that they had wings and the angels had halos and demons had horns, were flying around us all the time, the angels having come down from the sky and the demons up from deep underground. They believed that Satan, an angel who used to live in the sky with God and the other angels, had been thrown out of Heaven and now operated from Hell, deep underground.
All of those paintings and sculptures made over thousands of years' time of God and angels and demons and Satan and Heaven and Hell -- they weren't symbolic presentations of principles of physics which weren't elaborated until long after they were painted or carved -- they were realistic depictions of what people believed literally existed. People claimed to have seen God and/or Jesus and/or angels, and these people weren't thought to be liars or hallucinating or over-imaginative -- and they damned well weren't thought to have been speaking in parables either. What they said was taken literally and they were thought to be blessed.
The many people accused of witchcraft by the Inquisition and Protestant witch-trials, most of them women, were usually thought to have literally had sex with horned flying demons, as part of Satan's master-plan to conquer the world with evil.
Now, a few people still believe in all of the above. When "progressive" theologians say that those people are misunderstanding things which were never meant to have been taken literally, they're full of shit. It's as simple as that. When they say that the bible and Koran weren't meant by their authors to be taken literally, they're full of shit. When they say that God is physics or love or some kind of principle of idea, they're saying something completely different than the Bible and Koran authors. They've had the good sense to reject the literal existence of all of those supernatural things in the Bible and in all of those religious pictures, but if they remain practicing Jews or Christians or Muslims, then they hardly ever have the intellectual honesty to admit that they believe in things which are completely different than the things in their holy books. They've switched from the nonsense of preaching the literal belief in all of those things to the nonsense of preaching that those things weren't literally believed in for the great majority of the history of they claim are their religions. It's maddeningly seldom that a contemporary theologian will talk sense about the theology of past eras.