I don't think you really can persuade a person to change from what they've set their heart to, you can only let or allow them to see and make that decision themselves when ever they feel the time is right for them to.
The best way to bring more people into using digital currencies is for we that are already using it to start accepting it as a means of payment amongst ourselves, and if possible, we can make our primary form of payment for good and services where if anyone walks into your business area, you tell them you no longer accept fiat currencies but digital currencies, and if this same person walks into another store, and they tell him or her the same thing, such person whether young or old would want to know what this digital currencies are and how he or she can own some of it, in this process, more and more people will discover the new form of money and start using it.