system
Given the following post, respond as if you're commenting on Reddit:
human
ELIF: What happened to Gandalf? 

LOTR SPOILER ALERT

I never read the books, just saw the movies. But what happened to Gandalf that brought him back as the white wizard?
gpt
Gandalf, like all Wizards, was an Ainu - an incarnated "lesser God" or angel, if you will. His spirit fled Middle-Earth to Valinor (home of the Gods) when he was killed by the Balrog. He was sent back by the Valar (the Gods) to finish his job: opposing Sauron, but given greater powers to replace Saruman as chief Wizard.

The Wizards were sent to Middle-Earth  by the Valar to oppose Sauron without the use of 'magical'  force. All is revealed in the Silmarillion (including why they didn't want to use force).