The UK has some of the lowest levels of religiosity and belief in God in the world, according to a global study spanning dozens of countries.
The study by King's College London's Policy Institute found that large numbers of Britons do not believe in God, while those who say that God is not important to their life has reached record levels since the 1980s.
Researchers found that belief in Heaven and those praying and identifying as religious have also steadily fallen over the last four decades.
The findings are from the World Values Survey, an ongoing study of social, political, economic, religious and cultural values across 120 countries since 1981.
The latest data set, published today, compares data from the UK and 23 other countries, including the US, Italy, Sweden, Germany, France, Australia, China, South Korea, Japan, and the Philippines.
In the UK, 3,056 adults across England, Scotland, Wales and Northern Ireland were surveyed for the study by Ipsos between March and September 2022.
The findings reveal that belief in God has declined dramatically among Britons, from three-quarters who believed in God in 1981, to just under half (49%) in 2022.
Gen Z (those born after 1997) have the lowest levels of belief in God (37%), but the study also found a significant decrease in belief in the Pre-War generation, from 82% in 1981 to 59% today.
Only five other countries had lower levels of belief in God than the UK - China (17%), Sweden (35%), Japan (39%), South Korea (41%) and Norway (46%).
Just a third of Britons consider themselves to be religious today, compared to 57% in 1981. Only Sweden (27%), South Korea (16%), China (16%) and Japan (14%) ranked lower in this respect.
At the same time, the number of atheists in the UK has risen sharply from just 4% in 1981 to over a fifth (21%) today, with the popularity of atheism accelerating in the last five years.
Gen Z were least likely to see themselves as religious - just 27% compared with 46% of the Pre-War generation - and the most likely to identify as atheist (31%), although atheism has risen across all age cohorts.
Less than a quarter of Britons (23%) say that God is important to their life - level with France and higher only than South Korea (17%), Norway (16%), Japan (14%), Sweden (14%), and China (8%).
The proportion of Britons who say God is not important in their life has doubled since the 1980s, from 28% to 57% in 2022, a record high.
Less than a third of Britons (31%) see religion as very or rather important to their life, ranking higher than only four other nations - Australia (30%), Sweden (28%), Japan (15%), and China (13%).
In the UK, as belief in God has died away, so too has belief in Heaven, falling from 57% in 1981 to 41% today.
Belief in life after death has remained constant since 1981, with just under half of the population believing in this last year. Likewise, 26% of Britons said they believe in hell, remaining virtually unchanged over the last four decades.
Despite being less religious than older generations, younger people are more likely to believe in life after death - 51% of Gen Z, 53% of Millennials, and 52% of Gen X - compared with 35% of Baby Boomers and 39% of the Pre-War generation.
They are also more likely to believe in hell - 32% of Gen Z and Millennials compared with only 18% of Baby Boomers and 24% of the Pre-War generation.
Two in five Britons (42%) say they believe in Heaven, but this is lower than in many other countries, including Australia (50%) and the US (69%).
Levels of prayer and attendance at religious services were also found to be far lower in the UK than other countries. Only one in 10 people said they attended a religious service each week, changing little since 1981 but considerably lower than the US (29%).
And only 16% of Britons said they pray daily, ranking only above South Korea and China. The UK also has one of the highest proportions of people who say they rarely or never pray (63%).
Despite low levels of religious beliefs, the UK is one of the most religiously tolerant countries, with 82% saying they trust people of different faiths. The UK public are also among the least likely to say that their religion is the only acceptable religion (12%).
The study also found that confidence in churches and other religious institutions has risen in the UK in the last five years, from 31% to 42%.
David Voas, professor of social science at UCL, said, "The findings point to both the long-established erosion of religious involvement and to some interesting complexity in our self-perception and who believes what.
"The main story remains that most people in Britain aren't very interested in religion. That said, the glass remains half full when it comes to belief in God or life after death. Adults under 40 are much more likely than older people to call themselves atheists, but also to say that they believe in hell, which is a fascinating puzzle.
"While the British seem comfortable with their widely shared lack of religiosity, they have little objection to others being different, at least so long as religion doesn't intrude into public affairs. The survey even shows an unexpected uptick in confidence in churches and religious organisations."
Bobby Duffy, professor of public policy and director of the Policy Institute at King's College London, said: "Our cultural attachment to organised religion has continued to decline in the UK – but our belief that there is something beyond this life is holding strong, including among the youngest generations.
"This reflects a long-term pattern, where those who feel actively connected to organised religions have moved from a 'conscript' army in previous decades, where many more felt it was an automatic part of life, to a more 'professional' army, which are fewer in number but more dedicated in practice.
"This is an important period in the development of religiosity and spirituality in western countries like the UK, where the findings show that while the youngest generations continue to have lower attachment to formal religion, many of them have similar or even greater need to believe that there is 'more than this'.
"And of course, these sorts of international studies show that the decline of organised religion is not really a global story at all – as it continues to grow and flourish in many countries around the world, and these changes are really constrained to countries like the UK."
