Plain and simple. Tell them about what you know about bitcoin and how bitcoin changed your life. Some people say bitcoin is a scam but if you have first hand knowledge about it then tell them that it is not.
I think it's not so simple!
First, you need to try to convey information in a more understandable language.
Secondly, it is worth paying attention to the advantages that they would appreciate the superiority of the cryptocurrency and the future.