People are often ignorant. They judge people they don't really know. They may be told by those in their own religion or groups that your religion or group is a certain way, and they trust those people, so they don't open their minds to find out.

I also think some of them don't believe what they read. Those who might go to read texts on Wicca, for instance, may go into it with a closed mind, and what they see, they dismiss and think Wiccans are conspiring to make their religion out to be harmless (which it is, but the closed-minded person will refuse to accept that). Furthermore, one person might make up a story (sometimes to "join in") that they saw or heard about a witch sacrificing a baby or doing something horrible, and others believe them, so these kinds of idiot stories get around.

I'm sorry you have people who treat you like this. I have many Wiccan friends.