Have you seen this meme? It floats across my social media periodically:
It's a fun meme, and there is truth behind it, but it's also rather misleading.
Contrary to popular belief, Tolkien did not create his story world out of thin air as the meme suggests. As many fans know, Tolkien was influenced by mythology and his Catholic faith. And it's clear that he relied on his professional knowledge of old languages and linguistics in creating the tongues of Middle Earth. But there's more:
Tolkien also drew from the medieval texts he worked with as a philologist. From magic rings that make the wearer invisible to dragons guarding hordes of gold and much more, Tolkien himself was adapting and augmenting not only history, mythology, and theology, but also previous (medieval) authors' stories.
This shouldn't reduce anyone's admiration for Tolkien's work. If anything, it should make us admire him more; think of the talent and skill it took to pull from such varied sources to create something new! Tolkien's works are an accessible alternative to the medieval source materials he pulled from, but also excellent stories in their own right.
So yes, Tolkien's work is incredible. Yes, any adaptation of it should be done with respect and care, especially considering its fervent fanbase. But his work is not "sacred," as one Tolkein book purist put it on social media. It's not even wholly original as many assume. What it is, is creative and brilliant.