[Elladan and Elrohir]

Well, it's absolutely correct that Tolkien intentionally designed the end of the book to be bittersweet. Fading and passing away is a theme that runs throughout the entire history of Middle-earth. Whether it's the Two Trees, the Noldor, the Silmarils, Numenor, or Frodo, nothing lasts forever, no matter how great or glorious it is. One day, Morgoth will return, and the Dagor Dagorath will, we must assume, wipe out many fair things.

And whether Tolkien meant it to be or not, I think that this theme in his work is a direct result of his Christian worldview. Fading is the way things are. Man lives for seventy years or however long, and then one day he dies. And he's gone, never coming back. Ultimately, fading is a result of sin.

Not intending to preach, but this is why I would face total despair, if I were not a Christian. Being such, I believe that in God, there is something that will never pass away, and one day I will join Him in a place that will never fade. It is the way of the world that all things must pass away, but one day everything will change and we will be ushered into eternity.

All right, enough of the theology. If I've offended you, I apologize; like I said, I'm not trying to preach, proselytize, or shove my religion down your throat; I'm just stating my beliefs, and I think Tolkien's were similar. Certainly, we see more than an indication of this in his works. We can assume that Eru Iluvatar, the God of Ea, never fades or passes away. And think of Galadriel's final words to Treebeard. "Not in Middle-earth, nor until the lands that lie under the wave are lifted up again. Then in the willow-meads of Tasarinan we may meet in the Spring. Farewell!"