Relation Between Fairies and humans

Fairy List

Just as humans exist somewhere between fairies and giants, so do fairies lie between mortals and deities. Deities appear to exist physically alongside the giants as massive, awe-inspiring beings. For example, Loki is so large that he caused earthquakes when he was struggling beneath the ground. At the same time, it’s obvious that deities are able to change their size whenever it suits their interests - often choosing to enter human houses in desguise. Odin is believed to have become the leader of the fairies' wild hunt through the forest in a human form.
The differences between the ancient gods and fairies may be less than many suspect, just as it is with humans and fairies. On one hand, many of the fairies are descendants from deities or created by them. On the other, some fairies seem to come from the same place that deities are from and are even older than the deities themselves. For instance Zeus, the leader of the deities in Greek mythology, was raised by a nymph who kept him hidden from his father.
Examining the evolution of European beliefs about deities makes the definitive line between the worlds of fairies and deities even harder to see. Initially, Europeans had no real pantheon or concept of deity as it is now understood. Rome’s first deities were the spirits of rocks, trees, and animals. In other words before they worshiped gods, Romans worshiped fairies (Bailey, 1907).
Among the Celts, most gods were local gods rather than all-powerful deities. They were the gods of the rivers, mountains, trees, war, and more, making it hard to make a clear distinction between them and other spirits which might exist.
J. A. Maccullock (1911) believed that the divinities were the most important spirits which only later came to be deified. Oftentimes, these deities included among their ranks the spirits of the great humans who had died. This shows a connection not only between fairies and deities, but humans and deities as well.
These examples suggest that the only separation between deities and the other spirits (fairies) is simply that humans hold more respect for the deities.
Looking back to the roots of European beliefs, we see that within Central Asia there also appears to be little conception of deities. (tengerism.org) Even among the Greeks, deities often act as fairies. At one time, for example, Hermes took the boogyman’s place in coming down the chimney to scare naughty children thus cementing himself as a fairy. (Purkiss, 2007)
Perhaps then, fairies are deities who have not been conceived as such by humans. In other words, deities are hierarchically higher because of how humans regard them. Moreover, as we will see in the chapter “Fairies are Forgotten Gods”, deities can lose their godhood and turn back into fairies. This deification process can go beyond the fairy stage and down to the realm of humans where humans can become the deities that people worship. Nothing makes this clearer than the evolution of the wild hunt which was, at one time, led by Odin who had become a fairy.  However;
 “in the middle ages, when the belief in the old heathen deities was partly forgotten, the leader of the Wild Hunt was no longer Odin, but Charlemagne, Frederick Barbarossa, King Arthur, or some Sabbath-breaker, like the Squire of Rodenstein or Hans von Hackelberg, who, in punishment for his sins, was condemned to hunt for ever through the realms of air.” (Guerber, 1909)

What we see then is that while there are clear mythological lines between humans, fairies, and deities, it holds more in common with the line between children and adults then between one species and another.