The decline in faith is better represented as a gradual decline in the certainty of belief, rather than a fall in the number of believers, according to new research.

Ryan Burge, a professor of religious practice at the Danforth Center on Religion and Politics at Washington University in the USA examined new data from Pew’s Religious Landscape Study.

It shows young Americans are less certain God exists — but very few are becoming atheists.

It asks two questions: “Do you believe in God or a universal spirit?” and, “How certain are you about this belief?”

It shows not only that faith extends beyond convinced believers, but that disbelief is not nearly as firmly held as previously thought.

Moreover, a breakdown by age cohort shows that, while those “absolutely certain” in their belief declines with age, those who are “fairly certain” or “not too certain” increases. The figures for those born in the 1940s, from most certain to less certain faith, are 65pc/19pc/5pc/1pc, whereas for those born in the 2000s are 39pc/28pc/9pc/1pc.

Likewise, the corresponding figures for disbelief went from 4pc/4pc/1pc/1pc to 6pc/10pc/6pc/2pc.