Happy Tolkien Day!
From a letter to C. Ouboter, Voorhoeve en Dietrich, Rotterdam 1958
"As for 'message': I have none really, if by that is meant the conscious purpose in writing 'The Lord of the Rings', of preaching, or of delivering myself of a vision of truth specially revealed to me! I was primarily writing an exciting story in an atmosphere and background such as I find personally attractive. But in such a process inevitably one's own taste, ideas, and beliefs get taken up. Though it is only in reading the work myself (with criticisms in mind) that i become aware of the dominance of the theme of Death. But certainly Death is not the enemy ! I said, or meant to say, that the 'message' was the hideous peril of confusing true 'immortality' with limitless serial longevity. Freedom from Time, and clinging to Time. The confusion is the work of the Enemy, and one fo the chief causes of human disaster. Compare the death of Aragorn with a Ringwraith. The Elves call 'death' the Gift of God (to Men). Their temptation is different: towards a faneant melancholy, burdened with Memory, leading to an attempt to halt Time."
That is really interesting to see what Tolkien thought one of his themes were and i can see Death being one of the themes in LotR and in Sil and what Elves and Men thought of it in the long-term, and how they act towards it. The Lothlorien elves wanted always to preserve the past and looked back a lot in the Third Age. In the Second Age, the men wanted to be like the Elves and was curious about the Valar and the Blessed Realm and wanted eternal long life to evade death. That was their downfall of always wanting to be immortal and be like the elves. Elves wanted what men had or to preserve the past while men in the Second Age wanted to be the Elves. That is something to write more about. :)