As far as I can tell, this is for real. Here is a never-before-screened scene from Return of the Jedi, showing Luke being tempted by Vader and activating his lightsaber for the first time and becoming a Jedi Knight.
I realize that posting this officially confirms my status as a total geek. But I’m perfectly okay with that. If you feel the need to make this all theological, you could probably make this fit in the doctrine of sin somewhere – e.g. sin nature, temptation, fallenness, image of God gone awry, etc. – be creative.