What Samuel L. Jackson said and some confusion I had.
STAR WARS SPOILERS AHEAD
So one of the many things being debated is whether Finn is force sensitive. I had some confusion over this as Kylo Ren notices him at the start. Ren didn't seem to be paying attention to the fact Finn didn't join in when he was supposed to shoot the civilians. Yet Ren stops in the middle of walking to look at him and then releases his hold of the engery bolt. Later on he doesn't need to be told which Stormtrooper betrayed them because he remembers who caught his attention. Finn could very well have the potential to be a Jedi.
But turning on a lightsaber doesn't mean he's force sensitive. There's proof in the movies that you don't need to be one. Who uses one in Empire Strikes Back? Han Solo. He uses Lukes' lightsaber to cut his Tauntaun open. General Grevious wasn't force sensitive yet his mechanical body could still copy the movements Dooku taught him. Finn could still get the concept given his training (remember the "traitor" guy fight?) I think it's still open on whether he is or not.