Wait a minute. I though being a jedi (or sith) was necessary to use the force at higher levels. Yes luke commented that the force was strong, which only meant at the time that they were good candidates for jedi training, not that they could use the force wily nily without any training. Then what the hell was luke's jedi training about on dagobah if not for learning how to use the force.
Not at all. In fact, the Force has nothing to do with the Sith and Jedi orders beyond both organizations membership is comprised entirely of people who have the ability to use it in some capacity. Someone could learn to use the Force at a high level if they had access to the knowledge. The issue is that both orders hoarded holocrons and other materials on the subject in an effort to try and control what information was out there.