To show how isolated the Invisible Man is, Wells exposes us to variety of communities in The Invisible Man. There's the small village (Iping), the larger village (Burdock), the city (London), the intellectual community (the scientific world), the marriage (Mr. and Mrs. Hall), and just about every other community you can think of. (Landlord and tenant? Check. Friends? Check. Police officer and citizen consultant? Check.) Unfortunately for Griffin, he seems to be on the outside of each of these communities, which leads him to be the subject of gossip and rumors or even violence. Not that he doesn't deserve it (sorry, Griff).
The Invisible Man shows us that communities are necessary for human advancement. When the Invisible Man is on the outside, he's stuck.
The Invisible Man shows that there's no way to enter in to a new community if you don't already belong.