Not all mainstream religions deny that. Go to India (Hindu areas) and say you are God and the people might respond with "Hurray!". Hinduism's grand creation myth involves God splitting himself into countless pieces, and we are all those pieces, trying to work out how to come back together again, except we are confused and don't quite realize we are all the same thing, all fingers on the same hand so to speak.

Anyway, I'll go watch that video now.