How can I stop being someone's friend without losing our mutual friends?

Ok, so I have five friends and I love them all to death. However, three of said friends are very not good for my life. You see, they like to summon evil spirits and such things. I don't believe that way. They talked me into doing such things. My mom saw what we were doing and threatened to kick me out if I did anything like that again. I have to stop talking to said three friends, but I don't want to hurt their feelings because I have been friends with them a long time, and I still care about them. What do you think I should do?