Background
Jareth has been apart of the Jedi for as long as he can remember, only just barely remembering the faces of his mother and father from before being taken to the academy on Dantooine. He trained very hard, instantly falling in love with the Code, although he unknowingly took on a very one-sided interpretation of it. He was too young and still only an apprentice when the Mandalorian Wars started, and as such felt forced to listen to the Council's order to sit back and watch. This has left a large amount of guilt on Jareth's conscience as he always wanted to help, and felt like the Jedi should have gone to war against the Mandalorians. In the time since the end of the Mandalorian wars with his graduation into the rank of Jedi Knight, Jareth has made it his life goal to use his power to protect the republic. At least, what's left of it, and the citizens of the galaxy from the larger threats out there.
Motivation
Injustice - Slavery
Drive - Guilt
Belief - The Jedi
In short, Jareth is a young man who seeks to end the injustice of the Galaxy. Watching the council sit back and take a passive role in protecting the Republic and its peoples causes him immense distress, as he believes the Jedi should be more active in it's job.