I guess there are two discussions to be had here. The first is whether, in light of the author's explicit statements that he means the work to be Christian, we

I guess there are two discussions to be had here. The first is whether, in light of the author's explicit statements that he means the work to be Christian, we are still authorized as readers to abstract his text into a general idea of "the Hero's Journey." The second is whether there is anything distinctively Christian at all about LotR, when considered on its own terms. I would say that LotR objectively differs from the Hero's Journey in that it insists on mercy and the principled refusal of worldly power as its most central ideas.