I thought I'd start a nice friendly discussion between Tolkien fans and Harry Potter fans.
The object of the posting is to discuss the differences and similarities between the Harry Potter book series and Tolkien's Silmarillion, Hobbit, and LOTR series.
Note: This topic is not to debate whether the Harry Potter series is evil or simple harmless fiction.
I'll start off with something I noticed. While Harry Potter is a human learning to become a wizard, Gandalf the Grey, Sarumon, and Radagast the Brown are not humans. They are Maiar: Ainur of lesser degree than the Valar.
Gandalf's original name was Olórin amongst the Maiar. If I remember right, Saruman's original name was Curumo.
Sauron is also of the race of Maiar and was servent of Melkor (or Morgoth).
Melkor is also one of the Valar, and Tolkien's middle-earth equivalent to satan.
The Balrogs are listed as servants of Melkor (Morgoth) in the appendix of the Silmarillion. There they are described as demons of might and demons of fire... and scourges of fire and demons of terror in the Valaquenta by the Noldor. The Balrogs were once Maiar who joined and were corrupted by Melkor.
In his book series, Tolkien intended the Valar and Maiar to be angelic like beings. The powers they exhibit are not magic but natural to their nature. Even though Gandalf, Radagast, and Sarumon are referred to as wizards (Istari), they are not sorcerers.
Gandalf, Sarumon, and Radagast have taken on the form of humans (much as angels do), but that is not their original form.
It also seems to be a trend in the Tolkien universe that beings who utilize sorcery granted from Sauron become corrupted. Even the use of the Palantíri (a device created by Fëanor) is portrayed as dangerous and corrupting to men and maiar when they come under the control of Sauron.