A brief excerpt:
What am I saying? To the Christian March 25th is the day that Lucifer is defeated by means of the incarnation and death of Christ. Likewise, the day Sauron is defeated is also March 25th when the Ring was cast into Mount Doom. One might argue that Tolkien is preparing his reader for Christ by means of a story. After all, he does write of a pre-Christian world. It would only makes sense that there are foreshadowing of Christ to be found in it like there are in other pre-Christian cultures.