Well,I think you should not convince anyone to buy or invest in bitcoin especially to those people that not believe in bitcoin. Even your friend have a lot of money don't mind them and let them discover about bitcoin.
It's better to them to to save money than to invest in bitcoin.
Investment is based on individual,I can not advice anybody to invest in Bitcoin,because if I do,and they lose,they will definitely ask me to refund their money,or they will keep malice with me forever.The race to make money is an individual race,everybody has his own land to take.I can only advice someone and tell the person all that is involved in it.That it is always two sided,either you win or you lose.When you win,then the better for you,but when
You lose,you won't have to blame anyone for losing too.
What I won't advice anyone to do is borrowing money to trade.This is very risky,And very bad,and I won't for no reason advice anyone.