Thinkers About Community

Can anyone help with this?

I want to read a book of thinking about 'community'.

I mean, by those inverted commas, something like a particular take on community: how people can be together, or why they do, or why it is in our DNA (is it?) and why the word has so much in the way of  religous overtones... and is 'community' always  semi-religous? I'd like it to be a thought-book rather than fiction... but I'm not very good at reading heavy duty philosophy.

I'd be happy if it was old... if it was great... but I'll take what you got.  Reading lists please.