Luke Skywalker isn’t a Sith and he’s not a Jedi either.
There has been a lot of talk about Luke turning to the dark side in the upcoming movie Star Wars: The Force Awakens. Reasons for this are numerous, though flawed, and I would like to propose my own theory. After Jedi, Luke Skywalker became the only Force Master in the galaxy and also the only non-Jedi and non-Sith. He transcended the labels of Jedi and Sith and in so doing “balanced” the force and became the Chosen One.
Luke turning to the dark side wouldn’t fit in his story arc. At the end of Jedi, he chose not to kill his father, and didn’t give into the Emperor’s power. If he was a Sith after thirty years not only would that cheat the audience, it wouldn’t make any sense to his overall story.
However, Luke being a Jedi doesn’t make sense either. If you remember, Jedi and Sith are two religious terms to define and understand what the force means to the galaxy. While Luke was trained as a Jedi, he was also “trained” as a Sith by the emperor and Vader. He overcame their power, because he’s stronger, but I don’t think that means he ignores their teaching. After all, Luke did try to kill the emperor when his friends were in danger. Was that so wrong? He was trying to protect them.
I think Luke has transcended these religious terms of Jedi and Sith and has learned to control both light and dark, essentially becoming both. This puts him on a whole different scale of the force. He’s a “Force Master” rather than one or the other.
I think this makes the most compelling sense to Luke’s character arc and his journey. It also will allow J.J. and Lucasfilm to continue playing with moral ambiguity and Obi Wan’s “Point of View” speech. Luke will probably make some very morally grey choices, and this will stir up a compelling drama and story, not to mention shake up the dynamic of good vs. bad.
If you really think about it, this is the only logical choice to make within the story because it takes it in places we haven’t gone before and doesn’t subject Luke’s character to the stereotypical Jedi Master slot. It also raises a lot of questions about what we knew about the Force and morality in general. So, in conclusion, when we first meet Luke he will be a far different Luke, and one that we might not be sure if we can trust as we once did, but will not be either Jedi or Sith, but “Other”.