Is A.D. P.C.?

I've been reading about the Supreme Court's upcoming consideration of whether saying the Pledge of Allegiance is constitutional, or whether the "under God" part is an unacceptable bringing of religion into schools. It seems impossible to imagine that schoolkids might not be putting their hands over their hearts every a.m., or will have to recite some sanitized, ACLU-okayed version instead. It's true that I would probably feel differently if I didn't believe in God, and in our nation being under Him; but it's also true that eliminating any reference to religious belief from our schools and our society is going to be a pretty daunting task.

For example: Tonight I was doing homework with my daughter, and her job was to find answers to questions in her textbook. The lesson was on dates -- why we need them, what a timeline's for, how we determine them. One question asked how we number years, and in reading the paragraphs on that subject, it was clear that the answer was "forward and backward from the birth of Jesus Christ." There's really not any more P.C. way to explain A.D. and B.C., and I suppose as long as they don't make any claims about Jesus Christ being anyone's savior it's not specifically religious, but if a kid's going to be disturbed by saying "under God" in the pledge, isn't he going to be upset by this, too? Are we going to be forced to switch to something nondenominational like "Common Era" to avoid lessons like this? I think the founding fathers would be against it, but I'm not so sure about the ACLU.