Always plural for me if you are thinking of the collective noun (meaning young people): the youth of today are our future. My usage is like Ewie's. Maybe there's an AmE difference. The thing is, with concepts like collective imaginary, the meaning is broad and fluid. Your question I think-as, to be frank, it is not worded that clearly-asks whether it is appropriate to compare democracy and Islam, one versus the other, as equal, comparable entities. 1. The family has an Internet connection at home. 2.The family have an Internet connection at home. Which is the correct one? You would vote for the both sentence, wouldn't you? Some grammars distinguish between the dual nature of collective nouns as follows: i) When a collective noun denotes an undivided entity, a singular verb is usual, e.g. 2. The jury consists of 12 men and women from all walks of life. 3. The council is taking legal action against my noisy neighbours. And about time too.
