Take it from Satoshi's mouth: "If you dont believe me or dont get it, I dont have time to try to convince you, sorry".
Personally, my family doesn't get the need of it because "oUr LoCaL mOnEy iS FiNe"; and the typical criticism that it's not physical; and if I'm going to try to defend it, they're just like "ehh ok". So basically, they're not interested. So what do I do? Just go throughout my day normally. You really just cant get everyone to be interested in such a niche subject.
Some people take longer to fully understand things, especially if they're initially skeptic. I'm sure sooner or later they'll hear or read about it somewhere and want know more. Your job is to be there when they have question.
Some of my friends are skeptic about making money from online, and once I talk about bitcoin to them, they don't have a passion, and they let the chance to buy bitcoin at a low price. But in my family, although they don't know much about bitcoin, they let me to choose what I want to do, and after they knew that I am trying to make money from cryptocurrency, they only say "Oh, that's good for you, so you now can make money, we hope you can get huge money from that".
Yep, that is like a new power to me, and that makes me to feel better and want to earn more money.