It is interesting to watch the American political machine from the other side of the pond and observe the need for the president to say "God bless America".
The prime minister in the UK is far from being exulted as a demi-god and I think that is better for democracy. The issue of their atheism, religion or sexual orientation is not so important. However for a PM to say "God bless Britain" would be the kiss of death to his or her political career.
I think one thing which unwittingly fosters religious faith in the USA is the absence of a universal National Health scheme. It promotes the need for a large contingent of the less well off to demand a faith based safety net to compensate for the lack of the sense of well being which free access to socialised medicine provides.
Yes tax the religions and do grant them tax relief but only for their donations to external beneficiaries.