In an apocryphal work called The Forgotten Books of Eden, it is said that Adam and Eve dwelt in the "Cave of Treasures" after being cast out from the garden of Eden. It is interesting that in this apocryphal work, we see the nature of the devil. It says that he is hideous but is able to transform himself into an "angel of light." This is alluded to in 2 Corinthians 11:14 as well. This seems like exactly the kind of thing the devil would not want people to know about him and his nature. I think it's possible that this bs trope of "cavemen" and neanderthals (which are all fake history/hoaxcraft) are pushed because the devil and his hosts or armies were NOT allowed in the Cave of Treasures. The devil loves to mock things that he despises. The power of prayer is seen in this passage. The devil is not able to enter the cave whilst Adam and Eve are in prayer to Father. This all seems like information the wicked one does not want anyone to know about him. This could be why the verse in the NIV about prayer and fasting is removed, perhaps prayer and fasting is a very potent REPELLANT to the devil, his schemes, and his hosts.