The new study is based on data collected as part of the General Social Survey by researchers at the National Opinion Research Center (NORC) at the University of Chicago.

The researchers looked at data from 30 countries where surveys, taken at two or more time points between 1991 and 2008, asked residents about their belief in God. Participants answered three main "belief" questions, including their level of belief (from strong to atheistic), their changing beliefs over their lifetime and their attitude toward the notion that God is concerned with their personal lives.

[Read full story on religious beliefs by country and age group]

For level of belief, with the two extremes being "I am certain God exists," and "I don't believe in God," here are the results:

Percent of residents who said they were certain of God's existence:

  • Japan: 4.3 percent
  • East Germany: 7.8 percent
  • Sweden: 10.2
  • Czech Republic: 11.1
  • Denmark: 13.0
  • Norway: 14.8
  • France: 15.5
  • Great Britain: 16.8
  • The Netherlands: 21.2
  • Austria: 21.4
  • Latvia: 21.7
  • Hungary: 23.5
  • Slovenia: 23.6
  • Australia: 24.9
  • Switzerland: 25.0
  • New Zealand: 26.4
  • West Germany: 26.7
  • Russia: 30.5
  • Spain: 38.4
  • Slovakia: 39.2
  • Italy: 41.0
  • Ireland: 43.2
  • Northern Ireland: 45.6
  • Portugal: 50.9
  • Cyprus: 59.0
  • United States: 60.6
  • Poland: 62.0
  • Israel: 65.5
  • Chile: 79.4
  • The Philippines: 83.6

Percent indicating atheism:

  • East Germany: 52.1
  • Czech Republic: 39.9
  • France: 23.3
  • The Netherlands: 19.7
  • Sweden: 19.3
  • Latvia: 18.3
  • Great Britain: 18.0
  • Denmark: 17.9
  • Norway: 17.4
  • Australia: 15.9
  • Hungary: 15.2
  • Slovenia: 13.2
  • New Zealand: 12.6
  • Slovakia: 11.7
  • West Germany: 10.3
  • Spain: 9.7
  • Switzerland: 9.3
  • Austria: 9.2
  • Japan: 8.7
  • Russia: 6.8
  • Northern Ireland: 6.6
  • Israel: 6.0
  • Italy: 5.9
  • Portugal: 5.1
  • Ireland: 5.0
  • Poland: 3.3
  • United States: 3.0
  • Chile: 1.9
  • Cyprus: 1.9
  • The Philippines: 0.7

Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.