Leading British evangelist Canon J John has warned that the cultural climate for Christians in Britain has changed from support to opposition.

"For far too long in this country we have needed to do nothing to survive because we had the wind behind us," he says in a blog on the Huffington Post. Now, this has reversed.

"We need to realise that we are very much in opposition. The wind -- and it may soon be a very chill one -- blows in our faces."

He was responding to a Huffington Post poll this week that showed that more than half of Britons believe that religion does more harm than good and less than a quarter believe faith is a force for good.

Even one in five of those who claimed to be "very religious" said religion was harmful to society. A quarter said atheists were more likely to be moral individuals than religious people.

Fewer than one in ten said they were very religious and more than six in ten were not religious at all.

Canon John, director of the Philo Trust, said there were two possible responses to the findings. "The first is to turn inwards, to slip into the 'encircle-the-wagons' mode, worship behind closed doors and, in comfortable privacy, bury our beliefs. That may preserve our faith but what will be preserved is not an authentic Christianity. The second response is to accept the challenge, turn outwards and go out boldly to confront our culture. To do that will not be comfortable, but it will be authentic. We Christians in Britain need to be prepared to live more wisely, think more deeply and, just maybe, die more willingly for what we believe."