system
Given the following post, respond as if you're commenting on Reddit:
human
[LotR] Why is Gandalf considered so powerful?

#
gpt
First, some words about Sauron, since that is a worthwhile comparison:

Sauron, at his strongest, was physically powerful enough that the size of the army facing him was irrelevant. He could enter the fray and cause enough destruction and terror that his enemies would either rout or be slaughtered to the last man. He was only defeated by chance in a moment of hubris.

However impressive this display may have been, many scholars agree that *this did not represent his true power*. His most terrible work was in fact orchestrating the fall of Numenor, many years earlier. From a forgotten cell in the depths, he wormed his way into the confidence of the greatest men who ever lived, corrupting their hearts with madness and evil. He was able to steer the will of an entire nation away from the path of enlightenment and peace, until they in a righteous fury sailed West to make war on the gods themselves.

It is clear that, without Gandalf's intervention, the War of the Ring would have progressed quite differently. Sauron's true power was at work not on the battlefield, but in the hearts of his foes. Through the Palantir, Sauron sowed the seeds of despair in both Saruman and Denethor. The former defected to the Deceiver entirely, and was able to subject Theoden of Rohan to his will. Denethor had not the will nor the means to organize an effective defense of Gondor. Both kingdoms were expected to crumble with minimal effort... and they would have, if it had not been for Gandalf. 

Sauron's greatest power is the ability to encourage the worst in people to manifest -- and Gandalf has the power to do the opposite. Over and over we see those near him rise above themselves and become great: Bilbo becomes the greatest burglar in the world. Theoden breaks free from Saruman's thrall and leads his nation to glory from the brink of defeat. Aragorn realizes his true destiny as the King of Gondor, and rallies his beleaguered nation. Frodo Baggins and Sam Gamgee, diminutive folk of a forgotten people, are empowered to do the impossible and carry the One ring to its destruction.

These events were not accidents. There is hardly an event that occurs during the War of the Ring that cannot be traced back to Gandalf's influence. This speaks of unnatural foresight. Defeating the Balrog should not be taken lightly either -- it was a feat of supernatural exertion comparable to Sauron's physical display. But his true power, in the end, was used to undo Sauron's ruinous campaign of despair and replace it with the power of hope.