The role of religion in politics is a hot issue in Australia, from the horror stories of Catholic hospitals denying basic medical services to women, to Kevin Rudd’s charming characterisation of himself as a “Christian Socialist”.

It’s often assumed without question that religion is a rising influence in western societies – most notably perhaps by The Australian‘s Paul Kelly, who assures us that “These are not good days for secularists” and “God’s comeback is one of the dominant world stories of the past decade.”

But occasionally a note of reality creeps in. On Tuesday, Pamela Bone described Kelly’s view as “wishful thinking”, and cited figures to show that “the intensity of religious belief has been waning for years.”

Two further pieces of evidence have come in this week. First is a report from the Pew Research Center on the attitudes of young people in the US, cited on his blog by Andrew Sullivan.

Among the findings: 20% of American 18-26 year olds identify as atheist or agnostic, up from 11% in the 1980s; only 6% nominate a spiritual figure as “most admired”, compared to 15% of those over 26; and while a third believe in Creationism (yes, this is the US), that is easily the lowest proportion of any age group.

Then came a survey from the French daily Le Monde, which shows that in France, traditionally the greatest Catholic power, only a bare majority – 51% – now identify as Catholics; down from 67% in 1994. The number “without religion” has risen from 23% to 31%. (Despite the right’s paranoia, Muslims are only 4%.)

Even more interesting was what the survey found when Catholics were asked about what they actually believe. Only 52% of them regarded the existence of God as “certain” or “probable”. Just 38% believe in the virgin birth, and a strikingly low 18% believe in a “personal God”. Only 8% attend mass weekly.

It looks as if the long-term decline of religious belief is still in progress. Politicians trying to hitch themselves to the churches need to have a strategic rethink.