Hahahah this is pretty fucked up lol
I'm lucky that my parents don't know anything about btc or whatever...There wasn't a single news article about bitcoin in my country from the day it began.
If I was you,I would just show my dad some YT videos and see how that will go.
It won't help because his dad is a close minded person already because of a lot of illegal things that are coming out with the society on their place and the medium for those acts is with bitcoin. It's kinda hard to encourage and change the mind of his dad because his dad thinks that way by showing him on how you use bitcoin legally will simply make his mind change.
Exactly he just his father for what purpose he is using bitcoin. And where he is getting bitcoin. Suppose if he is making bitcoin from gambling then it is tough to convince. I think he will never convince if it happens. If he is making coins from any signature campaign or any other online work, then there is a possibility are there to convince his father.