Tolkien himself said to beware allegorical readings. He said had he sought allegory, by book III the rings of power would have been seized for good or ill, and the Hobbits discarded as irrelevant or enslaved. Likewise the palentir (!)
Tolkien also faced extensive criticism from Christians for a non catholic fictive world, something he easily disregarded as trite. He was a loyal devout catholic in every respect.
His biography by Humphrey Carpenter goes into all this.
J. R. R. Tolkien: A Biography, 1977