I am confused and disturbed by this. Will one of our German members report? How strong are these sentiments? About what percentage of the population holds them? What is your stance?
My immediate response is twofold, and I may be wrong on both counts:
1. I think it important that immigrants to a country adapt to that country--that they learn the official language (they needn't speak it exclusively), that their children attend school, that they try to meet the needs of the society in whose lands they have chosen also to call home. This is bloody ironic, I know, coming from a European descended American who knows little to nothing of the aboriginal peoples her recent ancestors displaced.
2. Still, yet, in defense (and STRONG defense) of the Muslims, they should NOT have to forfeit identity of their heritage, nor their religion, in order to live peaceably in Germany.
Muslims may change Germany significantly. Wherever there is a confluence of people, the culture shifts. It is the way of the world. It's scary, perhaps, but needn't be responded to with intolerance.