We in the US really ought to demand for a start, all sermons in the mosques now be delivered in English.
The Germans have started to demand German language sermons in their mosques.
We have to know what is being said.
There's really no problem in finding out what's said in the mosques. The Imams here find it necessary to communicate with the young people, and they use English.
In any case, that's not where the problem comes from ~ the real issue is the Koran itself, and the Hadiths.