Although within this community Bitcoin is practically the only currency in which everyone believes, just look around a bit and we will find thousands of people who think otherwise.
At this point I wonder, what reasons should we give these people to make them realise that Bitcoin is a right choice? The first argument that comes to mind to convince a person who is sceptical about Bitcoin, is first of all that with Bitcoin you no longer need to delegate the custody of your money to a third party (banks, mutual funds, etc.): you are the master and you hold them. What else would you add?
Trying to convince someone, especially a friend, to do something, and especially in the financial field, is the worst thing you can do because it can actually ruin relationships and even lives. You should explain why YOU decided to buy bitcoin (or any type of asset/investment) and then let them decide whether they want to do the same or not and make sure that there is no way they can blame you for something in case things go south.
One of Satoshi's most famous quotes is
"If you don't believe me or don't get it, I don't have time to try to convince you, sorry", so why should you?