tambourine - "Every Christian life strengthens the belief of the community. Muslims increase their community likewise, with big families....".
I disagree. For almost all other faiths apart from Christianity - faith and worhsip are bound up as part of daily life and routines, so yes, a sense of community does exist for these faiths.
I dispute that Christianity creates or furthers communities - from my epxerience, you will find more power struggles, small-mindedness, back-biting, and cabalism in Christian parishes than you will anywhere else in UK culture.