An atheist advertising campaign has been launched on buses across Britain.
A fund-raising drive for the promotion, carrying the slogan "There's probably no God. Now stop worrying and enjoy your life", raised more than £140,000.
The campaign, which will also feature on the Tube, is backed by the British Humanist Association and prominent atheist, Professor Richard Dawkins.
The Church of England said Christian faith allowed people to put their life into a "proper perspective".
A spokesman said: "We would defend the right of any group representing a religious or philosophical position to be able to promote that view through appropriate channels.
"However, Christian belief is not about worrying or not enjoying life."
Pressure group Christian Voice has questioned the campaign's effectiveness but the Methodist Church said it would be a "good thing if it gets people to engage with the deepest questions of life" and suggested it showed there was a "continued interest in God".
The advertisements will run on 200 bendy buses in London and 600 vehicles in England, Scotland and Wales.
The British Humanist Association said the buses carrying the slogan outside London would operate in Manchester, Birmingham, Glasgow, Edinburgh, York, Leeds, Newcastle, Dundee, Sheffield, Coventry, Devon, Liverpool, Wolverhampton, Swansea, Newport, Rhondda, Bristol, Southampton, and Aberdeen.
Four posters featuring quotations from the likes of Douglas Adams, Albert Einstein, and Katharine Hepburn will also be placed at 1,000 London Underground locations.
The campaign was devised by comedy writer Ariane Sherine.
Across Britain we are used to being bombarded by religious interests, not just Christians but other religions as well
Prof Richard Dawkins
She was inspired to seek donations after objecting to a set of Christian advertisements on a bus.
When people went to a highlighted website address, they were told that whose who rejected God were condemned to spend all eternity to "torment in Hell".
Ms Sherine said she sought donations for a "reassuring" counter-advertisement.
She said: "I think there have been a lot of people out there who have been looking at evangelical advertisements and not saying anything and thinking that these advertisements have been approved and just shrugging it off.
"Now finally they have an opportunity to express this feeling of exasperation."
Professor Dawkins made a donation of £5,500 himself.
He said: "Across Britain we are used to being bombarded by religious interests, not just Christians but other religions as well...
"In the House of Lords we have bishops sitting as of right and we are still very much dominated by religious interests."
Other supporters at the launch of the poster campaign included philosopher A C Grayling, Guardian columnist Polly Toynbee, and Graham Linehan, co-writer of the Father Ted TV comedy series.
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