The Gift of Death

[Ælfwine]

I much prefer being a Man. I don't know if I could endure being bound to Arda as long as it excists. And maybe it reallt is a gift to shape ones own destiny and not be bound by the music, and after death to pass outside the circles of the world. Do not forget that Death was given as a gift. I think that it is very well explained in The Music of the Ainur as written in The Book of Lost Tales:

Thou Melko shalt see that no theme can be played save it come in the end of Ilúvatar's self, nor can any alter the music in Ilúvatar's despite. He that attempts this finds himself in the endbut aiding me in devising a thing of still greater grandeur and more complex wonder: - for lo! through Melkohave terror as fire, and sorrow like dark waters, wrath like thunder, and evil as far from my light as the depths of the uttermost of the dark places, come into the design that I laid before you. Through him has pain and misery been made in the clash of overwhelming musics; and with confusion of sound have cruelty, and ravening, and darkness, loathly mire and all putresence of thought or thing, foul mists and violent flame, cold without mercy, been borne, and death without hope.

Rather more telling that the version in The Published Silmarillion, if you ask me.