I'm not a Christian, but here is the most damning collection of
critiques on the Harry Potter series that I know of :
http://www.cuttingedge.org/news/hpmain.html
The site is run by an "orthodox" Christian - as opposed to, say,
"charismatic"?
As for LOTR, there is an alternative, non faith-based
interpretation of his writings.
I can't remember the URL now, but it goes something like this : the
elves, dwarfs and other creatures are aliens who have roamed the
earth at some point in the distant past.
The various races have both worked together with and fought against
the humans who are the "native people".
At the end of the story, the elves are seen to be leaving in boats.
This may be considered an allegory which can be compared to, say,
the Vorlons of Babylon 5 leaving the known galaxy in their
starships.
And as for Frodo and his uncle joining them? They were invited, and
accepted the invitation, to make the trip "way out there" together
with them!
Incredible? I thought so too!