It used to be that an act of generosity or mercy would be called "christian" by many. I've always thought that was poor word choice, because those actions aren't really in particularly Christian. "Frank led me to Jesus by his great love of Christ. That was very Christian of him": good word choice. "Frank let me borrow his lawnmower. That was very Christian of him": poor word choice. It's an important word choice as well, because it implies that non-Christians lack those traits and belief that outsiders lack generic positive traits is a symptom of unwarranted discrimination and prejudice.
Luckily, nowadays you don't hear that phrasing very often. It sounds slightly archaic. But I recently overheard something here in San Francisco that disturbed me. Someone said "He helped me set up the event; he's a real liberal." Liberal here is being used in the same sense as Christian; a place holder for "good". This is disturbing because it implies that the members of this culture actually believe that conservatives lack personal, positive traits. That's simply not true, and it's foolish to think otherwise. That kind of attitude is exactly what we should be fighting: people are people, good and bad, no matter what their religion or politics are. Neither Christians nor liberals have any monopoly on kindness.