Politeness more important than Christ, right?

Doesn't a Christian know that a nonChristian does not "rest in peace" after death? Is it just a forgiveable convention to use that expression when someone dies? I think it's indicative of a compromised Christian understanding and it contributes to a blurring of the boundaries which we should be keeping sharp. Are we of this world or not? How far should one take politeness when eternity is at stake? Is it a service to anyone to perpetuate the fiction that you can reject Christ and still have a happy eternity?

Singer Mary Travers of Peter, Paul and Mary fame just died. Recently actor Patrick Swayze died. A while back actress Farrah Fawcett died. And of course Michael Jackson. Where are they now? Was any of them Christian? No. Then they are not resting in peace.