When I decided that I wanted to go Greek, one of my best friends at school was not cool with it at all. However once she saw how happy I was and met some of my sisters, she became more comfortable with it. Plus I make sure to spend time with her, so she knows that I'm not trying to "abandon" her.
People like to talk about things of which they know nothing about. A good friend of mine at home is going to be a freshman this year and she is considering rushing. Her boyfriend flat out told her no. He said all sorority girls do is "get drunk and invite naked men back to their rooms".

I told them that that is NOT what everyone does (and not to buy into rumors), and she is still going to rush! If you make an effort to let them know that you still want to be friends then you have done your part. If they are REALLY your friends, they will come around.
Megan