He is probably not capable of understanding the US dollar either. Ask him to explain how the USD works and what it is backed by. The money in your bank is not yours. It’s as simple as email.
Discussion
I live in Europe so it's about EUR but yeah it is the same with USD, still fiat. The thing with my father is that he thinks that Btc is some kind of scam like many he has seen in the past. in the fiat world. And that all those governments, banks and politicians may find some way to stop it, control it or delete it...