Where is Luke Skywalker?

This post may contain spoilers for Star Wars: The Force Awakens. I say "may" because I'm actually just making a guess, but if you don't want any crazy ideas clouding your first experience of the movie in theaters, you might want to stop reading now.

Someone else suggested that I write this down, presumably so that I can be mocked in two months when I am shown to be wrong. If I am, my only defense is that I haven't really been keeping up with the leaks for this production. I did the spoiler thing during the prequel era, and it's actually a lot of fun, but keeping up with all the spoilers is a lot easier when you're a college student. That being said, I think I have an answer to the question that everyone seems to be asking: "Why don't we see Luke Skywalker in anything?"

The answer is multifaceted, so I'm going to start in the middle and work my way out. The reason why we don't see Luke Skywalker is because he is a Jedi master, and like Obi-Wan and Yoda, he has become a hermit. Now, Obi-Wan and Yoda each had their own reasons for leaving the public sphere. Obi-Wan needed to lay low to watch over Luke and keep him safe from Vader. Yoda had watched his Jedi order crumble and his failure drove him into hiding to reconnect with the Force. Luke must have a similar reason for his seclusion.

When the Emperor died at the Battle of Endor, the Rebellion had a fully trained Luke Skywalker ready to bring the Force back into the galaxy. So why does the Force need to awaken thirty years later? There is a piece missing from this puzzle, and I have a guess about what that piece may be.

The rebellion would obviously want to add more Jedi to their roster. However, without a galaxy-wide blood test to detect Force-sensitive individuals, finding suitable students would be a challenge. They could rely on the Force to guide them to more students, but letting your only Jedi wander around the galaxy looking for a student would be a significant risk. Fortunately, we know that the children of Force-sensitive parents are also Force-sensitive. If either Luke or Leia had a child, that child would be the ideal first student for the new Jedi order.

While Luke's romantic prospects are looking quite bleak at the end of Return of the Jedi, Han and Leia's relationship is heating up, so it seems quite likely that Leia will have the first child, and that he will be trained in the Force from a young age to help the Rebellion in future missions against the still standing Empire.

Unfortunately for the Rebellion, Luke's own training was more than a bit abbreviated, and his first student will be in for a rough time as Luke muddles through passing on the little that he knows of the Jedi way. I theorize that eventually Leia's son becomes captivated by the work of his grandfather, Darth Vader, and turns away from Luke's teaching to found the Knights of Ren and regain control of the galaxy.

Luke, devastated by his failure, vows never to take on another student and goes into hiding so he cannot do any more harm. Thus, when Leia's son begins to decimate the remnants of the rebellion, a new Force-sensitive individual, Finn, must search for the disgraced Jedi and beg him for training before everything the Rebellion fought for is destroyed.

Like I said, this is only speculation. I've tried to avoid spoilers for this film, so maybe something big has already leaked that contradicts this theory, but I think it's reasonable, and matches the overall tone of the Star Wars saga.

Bonus Article: Where is C-3PO?

Another character notably lacking in the promotional materials is C-3PO. His history throughout the original trilogy was that he was property of Leia (or her family). I suspect that when Leia's son left to form the Knights of Ren, he took C-3PO with him.