Anyone who has ever taken any interest in French current events is well aware of it's changing demographic, but it's one thing to read about it and another to see it firsthand. The country is historically catholic, but because of the huge waves of North African immigration and the decline of catholic influence, you're more likely to see people going to the mosque than going to mass. This is especially apparent in Echirolles, where a large majority of people aren't what the French call francais de souche (literally souche means stump, and it refers to a person who is "pure" French, or whose French roots go back generations).
Case-in-point: teaching a Christmas lesson. This is the last week before the winter break so I decided to have a low-key Christmas-themed coloring activity day with my 2nd/3rd grade students (I'm just as ready for break as these kids are, and I had no desire to try to talk over a class of 20 screaming kids for 40 minutes). I started off the lesson by asking the class who celebrates Christmas, expecting maybe half the class to raise there hands. Three kids raised their hands.
"Okay, who doesn't celebrate Christmas?" Almost every hand shot up. Instead, most of them celebrate l'Aïd (explanation here). From what Wikipedia tells me, it's a celebration of Abraham's willingness to sacrifice his own son before God intervened.
(Side note: I asked the students what traditions they have, and I got a lot of the same responses I got when I asked about Christmas traditions in some of my other classes (family, food, snowmen, etc.). Then one girl bluntly said they kill a sheep. I was a little shocked., Thinking maybe I understood her wrong, I moved on to the next kid, but then I turned to her again, too curious to resist: "like...a live sheep?" A few of the kids made the knife -across-the-throat gesture and the teacher looked at me and gave a slight shake of the head. I'm not quite sure if he meant "don't get into this" or "she's bs-ing you.")
At the same time it's interesting to see the interaction between this and laicité, the French version of separation between church and state which has become something of a national obsession. For example ever since 2004 students are forbidden from wearing any sort of religious symbols, be it a cross on a necklace, a headscarf, a yamaka, etc. So often here you'll see students or, in my case teachers, take off their headscarf before entering the school, and then putting it right back on as they leave for lunch.
I'm not making any judgments, just making observations, just want to make that clear, these subjects are always a little touchy.