Are you asking us whether the downfall of British white culture is because of the influx of other cultures and religions leading to a dilution of systemic Christian beliefs in the UK?
Surely that would be a paradox, since if these people were downgrading our culture with their religious over-burden then general society would revolt? The downslide of Christianity in the UK has little to do with other cultures and antisocial behaviour, merely the cyclical nature of humankind in rejection of old beliefs and the reversion into newer (or older) beliefs or just a general lack of any beliefs at all. The revolt tends to be more social based, jobs, housing, benefits etc (or anything the Daily Mail says it is).
I don�t think Muslims, Sikhs or any other religious base would try to change our culture � although this is possible if many non-believers start believing and Christians convert � but would prefer their culture to exist within our culture to the point of tolerance and mutual acceptance.
Multi-cultural belief systems are not the cause of social problems in the UK, people and policies are. Or am I wrong and should I convert?