We know that men were made just a little lower than angels. We also know angels were created before men. We know angels have the ability to choose to serve God or to rebel against Gods will. Angels have spirits because the scriptures state that angels are ministering spirits. Angels have several different "classes" - there are high angelic beings such as Seraphim and Cherubim, there is the Archangel, and then we have messenger angels and ministering angels.
There are angels that can take on the form of men, and that angels can even marry and have children by men (Genesis 6). We know that the fallen angel known as Satan was in the garden of Eden in the form of a serpent prior to the creation of man. (Gen 1 -3, Ezekiel 28)
Now why would Christians balk at the existence of Elves? First, they have been misled by "fairy tale" stories of which 90% portray Elves as what they are NOT. So let's see what Elves are not.
Elves are not, 1) Santas helpers,
2) Harry Potters House Elves
3) Small Leprechaun type beings with sharp features and pointed ears
4) Small winged creatures that sit on mushrooms and flowers
5) Small fat creatures that live inside trees, in the leaves, or underground...
What Elves ARE:
1) Persons of human size and physique
2) May be slightly more intelligent than average humans
3) Have spiritual abilities and knowledge greater than humans
4) May have pointed ears, but not the exagerated ears portrayed in artwork and the movies.
5) Have been historically persecuted by organized religion in much the same way true Christians have been persecuted by organized religion. (The most famous being the Albigensian crusade in France)
Obviously the organized mideaval church considered Elves to be as much a threat to them as heretics. because Elves were close to nature they were often accused as witches. Some Elves were pagan, but others were Christian (like the Albigens/Cathars) - but the Church persecuted them all the same.
Many Christians deny the existence of Elves by claiming Elves are not mentioned in the Bible. But there was no word for "Elf" as we know it, and Elf is a more recent translation of the Scandanavian word "Alfar," and the Old English "Aelf."
As I've said, there is also no word for "human" (homo sapiens) in scripture either, though most Christians assume "man" and "men" refer to human beings. Interestingly, the "mighty men, men of renoun" mentioned in Genesis 6:4 are translated from the words "gibbowr " (mighty men) and "enowsh." Gibbowr means a strong, mighty, or brave man. Enowsh means "a man, mortal man, person, or mankind." Yet these people were actually hybrids created by angels (sons of God) intermarrying with humans!
This deserves greater study because it is assumed by most Christians that ALL the offspring of these angelic/human uniones were evil. It appears that the giants mentioned in Genesis 6:4 may have all been evil. (Giants is translated from "nĕphiyl" the word we know as "Nephilim"). But then we have these "mighty men of old, men of renown" who, from the proper translation were "strong, mighty, brave men (heros) who were men of renown - famous and of great reputation." Renown is translated from the primitive Hebrew word "shem" which is exactly the same name Noah gave to his firstborn son, Shem, who happened to be the father of the semetic tribes! Why would Noah, a righteous man, name his firstborn son the same name given to the mighty men of renown if the mighty men of renown were really evil?
I believe the "mighty men of renown" were (obviously) a hybrid race with angelic ancestry. They were not the evil ones.
So, to conclude: we most certainly DO have evidence of people in Scripture who are not of the human race. We have several types of angels: beings only slightly higher than men, and we have different types of hybrid born of angelic and human unions. Tolkiens mythology, (based on history), portrays Elves "awakening" upon Earth, and in the very beginning we see that some of the Elves marry beings called the Maiar, who are angelic beings.
For those who argue that Elves are not mentioned in the Bible, I would ask you to reconsider in light of this evidence. Dinosaurs are not mentioned by name in scripture either, but we know they did exaist because of fossil discoveries, and in the Bible there are mentioned creatures like Dragons, Leviathan, and Behemoth which do appear to fit the descriptions of dinosaurs. Likewise we have people in the Bible, from Adam and Eve prior to their fall, Melchizedek, and the mighty men of renown who do appear to fit the description of true historical Elves.