According to a survey conducted in France in April 2023, 44 percent of the respondents affirmed they believed in God, and there were 56 percent of the surveyed who defined themselves as non- believers. Since 1947, French people's faith in God kept slightly decreasing, indeed in that year there were 66 percent of respondents affirming they believed in God, and there were only 55 percent in 2004.

The global population of Buddhists is projected to slightly increase up until the year 2030, at which point it will begin a gradual decline. In terms of its share of total world population, however, Buddhism has already seen a decline from over seven percent in 2010, with this being projected to decline further to close to five percent in 2050. This decline is related to Buddhism being popular in countries whose populations are in a natural decline, such as Japan or South Korea (and Thailand in the near future), as well as demographic developments in countries that have a policy of state atheism, such as China or Vietnam.While this decline in its traditional regions of influence in East and Southeast Asia will cause an aggregate fall in the number of Buddhists, there is likely to be some growth in other regions of the globe, such as Western European and North American countries, where the popularity of the ideas of Buddhism have grown in influence in recent decades.

As of 2010, Christianity was the religion with the most followers worldwide, followed by Islam (Muslims) and Hinduism. In the forty years between 2010 and 2050, it is projected that the landscape of world religions will undergo some noticeable changes, with the number of Muslims almost catching up to Christians. The changes in population sizes of each religious group is largely dependent on demographic development, for example, the rise in the world's Christian population will largely be driven by population growth in Sub-Saharan Africa, while Muslim populations will rise across various regions of Africa and South Asia. As India's population is set to grow while China's goes into decline, this will be reflected in the fact that Hindus will outnumber the unaffiliated by 2050. In fact, India may be home to both the largest Hindu and Muslim populations in the world by the middle of this century.

Although traditionally a Catholic country, Spain saw a decline in the number of believers over the past years. Compared to 2011, when the share of believers accounted for slightly over 70 percent of the Spanish population, the Catholic community lost approximately 15 percentage points of their faithful by June 2025 with a share of 56.1 percent of the surveyed population. Believers of a religion other than Catholicism accounted for approximately 3.6 percent of the Spanish population in 2025 according to the most recent data. A Catholic majority, a practicing minority Going to mass is no longer a thing in Spain, or so it would seem when looking at the latest statistics about the matter: over 47 percent of those who consider themselves Catholics almost never attend any religious service in June 2025. The not so Catholic Spain Around 37 percent of the surveyed population stated to be either non-believers or full atheists in 2025. Non-believers or people that do not have a religious faith fluctuated over the past years with the latest figures showing a 21 percent of people that categorize themselves as so. The share of Spanish atheists is on the rise according to the most recent surveys, taking up 13.3 percent of respondents in June 2025.

The share of Swedes who believe in God declined continuously since 2010. While ** percent of the respondents believed in God in 2010, the share had dropped by ** percentage points in 2024, amounting to ** percent.

In 2018 just over a third of people in the United Kingdom identified as being Christian, compared with two-thirds 25 years earlier in 1983. During this time period the proportion of people who identify as Christian has declined dramatically, while the proportion of irreligious people has grown,

In 2024, almost four in 10 Polish believers professed faith and practiced it regularly, an eight percentage points decrease compared to 2020.