Whoa, it's interesting. I never heard about this sign on the ceiling! Here in Europe, you can find the Holy Bible in the hotels.
It's also strange for me, that a Mosque is the first building at a new residential area. I grew up as a Christian, but we hardly build new churches. It's a really rare event.
I think that the most important lesson was I learned during my religious education that we should respect the others and their believes.
Fortunately, I've got a lot of friends with different religions (Catholic, Islamic, Jewish) and all of them tolerate the other. I wish it were all around the world.