Love them or hate them, the Prequel Trilogy films forever changed our understanding of the Star Wars universe. It is through the Prequels that we learned about the Sith and the Rule of Two, virgin births via the Force, the much maligned midichlorians, and we were introduced to the concept of the 'Chosen One'--a prophesied being who would bring balance to the Force. As we saw in Revenge of the Sith, it seemed even the esteemed leaders of the Jedi Council weren't quite clear on what exactly that meant, and in the intervening years since the last film, the fandom has gone to quite some lengths to square this against everything we know transpires in the Original Trilogy.
The Clone Wars, which are still considered canon, has an entire story arc play out showing us Anakin Skywalker being confirmed as the 'Chosen One' while on Mortis. With these things in mind one of the challenges for the Sequel Trilogy is squaring away these canoncial truths, while selling us on a new story that sees the rise of evil in the galaxy less than 30 years after the Chosen One has completed his mission. But there is a key quote early in The Force Awakens that seems to do just that:
"I have traveled too far and seen too much to ignore the despair in the galaxy. Without the Jedi, there can be no balance to the Force." Lor San Tekka
In a blink and you'll miss it moment, Lor San Tekka seems to explain the mechanism by which the Force remains in balance -- the existence of the Jedi. This would mean Anakin served his role as the Chosen One by fathering Luke, who upon the deaths of Obi-Wan and Yoda, and turning his father back to the light before he too becomes one with the Force, becomes the last Jedi. This leaves the door open to honoring the concept of the Chosen One and the events of the previous six movies, while making it reasonable for a resurgence of the Darkside.
Now, the Star Wars databank describes San Tekka as belonging to the Church of the Force, which itself is described as an "underground faith that believed in the ideals of the Jedi Order" and maybe he is nothing more than a zealot, but that doesn't seem very likely. As has been pointed out, his opening lines seem to be a nod that the Sequel Trilogy is setting out to fix the past mistakes of the Prequels.
Part of the fun of having three new Star Wars movie is that we are invited to speculate and discuss til we're bluer in the face than Max Rebo. So what do you think, did Lor San Tekka spell out the purpose of the Chosen One, or is that crazy Rey theory not so crazy after all?