The problem is not that George thinks he's chosen by God or that he thinks he's the Pope-by-proxy; the problem is that the whole nation was founded by people who were (by today's standards, anyway) devout christians, so traditional christian religious ethics are inextricably linked to the constitution and laws of the country.
(by the way - hello everyone, i'm the Corinthian, and this looks like a not-entirely-terrible forum site you've got here)