David Cameron has urged the Church of England to lead a revival of traditional Christian values to counter the country's "moral collapse".
In a rare foray into religious issues, the Prime Minister said the values of the Bible "go to the heart" of what it means to be British.
Urging the Archbishop of Canterbury to "keep on the agenda which speaks to the whole country", he said the head of the church had every right to engage in political debate.
Addressing senior clergy at an event to mark the 400th anniversary of the King James Bible, Mr Cameron said "live and let live" had too often become "do what you please", as people shied away from saying things were right and wrong.
This "passive tolerance" of immoral behaviour had helped fuel the summer's riots, excess in the City, MPs' expenses abuses and Islamic terrorism, he said.
He confessed to being only a "vaguely practising" Christian who was "full of doubts" about big theological issues. But he insisted: "We are a Christian country. And we should not be afraid to say so."
The church and the Bible were "inherently involved in politics" because it involved many moral questions, he said, addressing directly recent criticisms of coalition policy by Dr Rowan Williams.
"I certainly don't object to the Archbishop of Canterbury expressing his views on politics. Religion has a moral basis and if he doesn't agree with something he's right to say so. But just as it is legitimate for religious leaders to make political comments, he shouldn't be surprised when I respond.
"Also it's legitimate for political leaders to say something about religious institutions as they see them affecting our society, not least in the vital areas of equality and tolerance. I believe the Church of England has a unique opportunity to help shape the future of our communities. But to do so it must keep on the agenda that speaks to the whole country."
Mr Cameron made clear that he was not suggesting that having a different faith, or none, "is somehow wrong". "But what I am saying is that the Bible has helped to give Britain a set of values and morals which make Britain what it is today. Values and morals we should actively stand up and defend."