What is it about American society that makes the religious faith of immigrant communities atrophy?

On 8 April, I made the 2.5-hour drive to the National Shrine of Divine Mercy Shrine in Stockbridge, Massachusetts for Divine Mercy Sunday. And how could I not? Judging by the licence plates in the parking lots, pilgrims travelled from every corner of the United States. According to the programme, many more flew over from Europe. I practically live down the street.

It was a deeply moving occasion, despite Mother Nature’s lack of cooperation: it was finger-numbingly cold, with snow flurries dropping in and out. Yet 15,000 pilgrims descended on the little mountain town, bundled in parkas and blankets. Some charitable souls drifted through the crowd passing out hand warmers.

Aside from the official proceedings, what struck me most was the demographic make-up. There were Hispanics, Filipinos, Africans, and Chinese – but hardly a Caucasian in sight. That’s grossly unrepresentative of the national Catholic population: 59 per cent are white, 34 percent are Hispanic, 3 per cent are Asian, and 3 per cent are black.

Of course, this has nothing to do with race and everything to do with trends in migration. Immigrants, whatever their faith tradition, tend to be more devout than their native-born counterparts. This is true even in countries like Sweden, where predominantly-white immigrants from Poland are contributing to a boom in the Catholic population.

But are these new Catholics a permanent feature of American and Western European countries? That seems doubtful. A new Gallup poll demonstrates that the rate at which Catholics attend Mass continues to fall since 1955, from 75 per cent to 39 per cent. This, despite the fact that the nominal Catholic population has grown considerably thanks to mass immigration from South America. Meanwhile, attendance at Protestant services has remained fairly stable.

The lack of Protestant immigration actually gives them an advantage with this metric. The children or grandchildren of immigrants who stop practising the faith are more likely to identify – if only nominally – with their family’s religion. Because Catholic immigration is so high, there are many “cultural” or “lapsed” Catholics: those who identify with the Faith, but don’t attend Mass. Meanwhile, Protestants who have “un-churched” are more likely to identify as irreligious.

Curiously, we see the same trend in Islam. A recent Pew survey shows that, while America’s Muslim population has risen by 50 per cent in the last decade, 23 per cent of those raised as Muslim no longer identify with that faith. That means roughly 1 in 4 Muslims in this country will apostatise. For comparison, 21 per cent of those raised Catholic have left the Church, according to a 2015 Pew survey. Americans are un-mosquing at an even faster rate than they are un-churching.

So, the good news is that the Church is probably not under-performing compared to its Protestant or non-Christian counterparts. The bad news is that something about American society causes religious faith to atrophy among immigrant communities of all creeds, races, and national origin. Here, again, Pew’s study of Islam in America is enlightening. Nine per cent of ex-Muslims converted to a different faith, and one per cent said they were actively searching for a spiritual path. That means only 10 per cent remain open to engaging with organised religion. The other 90 effectively become secular or “spiritual-not-religious”, which usually amounts to the same thing.

Clearly, there is something in our culture that discourages religious belief and practice. What that factor is, exactly, is another matter. But when we consider trends in un-churching (and un-mosquing), we should be careful not to overemphasise immigration statistics.

Rather, we should focus on how this secularising influence will affect social cohesion. Consider the ghettoisation of British Muslims and the rise of the homeschool movement among American Christians. Both can no doubt be attributed, at least in part, to a perception among devout families that their children are more likely to abandon their faith if they are exposed to “mainstream” Western society. They see our culture as hostile to their values and customs – to religion itself. And, if you crunch the numbers, they’re not exactly wrong.