Why are athiest people always so offended when you bring up Jesus Christ but will be okay practicing...?

Well, I have never had a Buddhist, Hindu, Muslim or Jew push their religion down my throat. I can't even begin to count how many times I have been shouted at my angry Christians telling me to repent and that their lord will save me. I mean, how do they know what I've done or not done. And this isn't even mentioning the nuns who try to persuade me to sign an anti gay adoption petition. Yeah, like I'm going to sign that.