They didn’t do it to protect him. They used him.
I strongly disagree. I think this is the wrong take. See below.
adywan said:
Don’t you think that suddenly finding out , from the guy you were trying to kill, that he is your father and that the people who you thought were trying to help you were lying to you for their own gain, wouldn’t cause this kid some serious pain? That could screw someone up.
They weren’t lying for their own gain. They were protecting him from turning to the dark side. Luke started the trilogy young and naive and inexperienced. He gave into his impulses easily. Do you think it would have been a good idea for Obi-Wan to tell Luke: “hey kid your dad’s a mass murderer and he abandoned you and your family. Your whole life is a lie!” Come to terms with that!
Or what if Yoda had told him, “hey Vader is your dad, if you go fight him he’s going to ask you to join him and you can rule the galaxy”.
No way man. Their goal was to train him so he could be mature and wise enough to deal with all of that when he was ready to do so in a healthy manner, and still turn out to be a good person, and save the galaxy.