Tolkien believed devoutly that there had once been an Eden on earth, and that man’s original sin and subsequent dethronement were responsible for the ills of the world; but his elves, though capable of sin and error, have not ‘fallen’ in the theological sense, and so are able to achieve much beyond the powers of men. They are craftsmen, poets, scribes, creators of works of beauty far surpassing human artefacts. Most important of all they are, unless slain in battle, immortal. Old age, disease, and death do not bring their work to an end while it is still unfinished or imperfect. They are therefore the ideal of every artist.
These, then, are the elves of THE SILMARILLION, and of THE LORD OF THE RINGS. Tolkien himself summed up their nature when he wrote of them: ‘They are made by man in his own image and likeness; but freed from those limitations which he feels most to press upon him. They are immortal, and their will is directly effective for the achievement of imagination and desire.’
Humphrey Carpenter: J.R.R. Tolkien: A Biography