Pope Benedict XVI told UK politicians gathered in Westminster Hall that religion needs to have a central place in public life.
Religion was not a problem for legislators to solve, but "a vital contribution to the national conversation."
"I cannot but voice my concern," he said, "at the increasing marginalisation of religion, particularly of Christianity, that is taking place in some quarters, even in nations which place a great emphasis on tolerance.
"There are those who argue - paradoxically with the intention of eliminating discrimination - that Christians in public roles should be required at times to act against their conscience.
"These are worrying signs of a failure to appreciate not only the rights of believers to freedom of conscience and freedom of religion, but also the legitimate role of religion in the public square."
He invited his audience to seek ways of promoting and encouraging dialogue between faith and reason at every level of national life.
It was, said one newspaper, the first time in many a year that religion and its role in modern society had been raised so forcibly in the UK.
Isn't it a pity that someone had to come all the way from Rome in order to say it? It is sincerely to be hoped that politicians will take notice.
On a papal visit in times past, the focus would probably have been the difference between Roman Catholic and Protestant faiths. The focus on this visit seemed to be Christian unity in the face of militant secularism.
Shortly before the Pope's arrival in the UK, the Guardian published a letter signed by 50 people, many of them left wing atheists, protesting at his visit. Some of the people who signed the letter have said some pretty awful things about the Pope.
Atheist Richard Dawkins called him "A leering old villain in a frock. . . whose preaching of scientific falsehood is responsible for the deaths of countless Aids victims in Africa." Vice president of the British Humanist Association Claire Rayner called him "this creature."
Why are atheists so vituperative? I came across a quote by Christian apologist Dinesh D'Sousa that I found interesting.
He says: "One reason I think is that they are God-haters. Atheists often like to portray themselves as 'unbelievers,' but this is not strictly accurate. If they were mere unbelievers they would simply live their lives as if God did not exist.
"I don't believe in unicorns, but then I haven't written any books called The End of Unicorns, Unicorns are not Great, or The Unicorn Delusion.
"Clearly the atheists go beyond disbelief; they are on the warpath against God. And you can hear their bitterness not only in their book titles but also in their mean-spirited invective."
Do you think this might be the reason atheists speak the way they do?