Dek Rollins said:
They are one with the Force. There’s your perfectly good explanation.

I can live with that rationalization

The purpose of that whole ending was that Anakin overcame the darkness inside of him and redeemed himself. Luke could sense the good in him, and was able to bring it to surface, in spite of Vader claiming it was to late for him.

I mean even someone like Gary Ridgway has good inside of him but even if he did a commendable act that doesn’t mean he’s instantly going to turn into a good person. That’s how I feel Anakin was portrayed at the end of ROTJ.