Nigeria, Brazil, India and Morocco are among the most religious nations in the world, according to a major study on faith released Tuesday.
More than 96 percent of the population in these countries described themselves as religious in the survey conducted by the German think tank Bertelsmann Foundation.
The study distinguished between religious and highly religious people. People that are classified as highly religious are those that worship and pray regularly and attach a high relevance of faith in their lives.
"Highly religious people are those for whom religious ideas play a decisive role in their personality," the study explained, according to Pakistan's The News. "They often see experiences and behavior in a genuinely religious light."
Guatemala, Brazil and Indonesia have the greatest percentage of deeply religious people among the 21 countries polled, according to the survey.
In Nigeria, a country roughly evenly split between Christians and Muslims, 92 percent of the population said they are highly religious.
The United States also had a notably religious population with 89 percent of its people describing themselves as such. Moreover, the majority of Americans (62 percent) consider themselves to be highly religious.
However, Europeans overall were significantly less religious than Americans and the rest of the world. The most religious nations in Europe were Italy and Poland – overwhelmingly Catholic countries – with about 87 percent of their citizens claiming to be religious.
Moreover, 40 percent of the citizens in these two countries said they were highly religious – a statistic higher than that of Turkey which has a Muslim majority.
Meanwhile, Germany, Austria and Switzerland had an average 70 percent religious population and about 20 percent highly religious population.
Interestingly, in Germany, nominalism is high with one in six church members describing themselves as non-religious. One in three citizens with no religious affiliation consider themselves religious.
The least religious country in Europe is Russia with 50 percent saying they are religious and only seven percent, highly religious.
Besides Russia, the study found that Thailand and France were other nations with the smallest percentage of people who said religious belief was important in their lives.
The worldwide opinion poll questioned 21,000 adults in 21 countries and presented the detail results in Berlin on Tuesday.