Here is an interesting article from the Bangkok Post. The Philippines rates as the most Christian country in the world with 94% believing in God, Chile second with 88% and the US third with 81%. http://www.bangkokpost.com/news/asia/289355/philippines-leads-world-in-belief-in-god
I think the article is a bit unclear on where they draw the line between Christianity, Monotheism, theism, church membership and belief. It definitely doesn't add up with the wikipage and doesn't include all countries (which from a reliability point of view is not necessarily a bad thing). That being said, it's very hard to survey these things. The link you give doesn't link to any paper, but hints that the survey was taken in 1991, 1998 and 2008. Exactly how they gathered the data is unclear, the time steps seem a bit spacious. Ok, so I looked up the research. It says that 94% of Philippinos _always have believed_ which is different from being a believer. If that is the case, then the Phillipines topping the list at 94% doesn't seem as implausible. NORC uses the words "strongest beliefs", not "most Christian".
2/3 of all Germans are believing in god - 4/5 of all Americans are believing in god and 15/16 of all Philipines are believing in god. In the same rank should be the intensity of the belief in god of single persons, if the psychosociological methods we are using worldwide are correct. If I take the intensity of the belief in god of Germans with 100%, then Americans would believe in god in an intensity of 120% and Philipines would believe in god in an intensity of 140%. My pleasure. http://youtu.be/nWDqG0IvGRc
Yes, well, my guess is that NORC uses "strongest beliefs" to get out of actually pinning down the criteria they use. On one side, it's bad to pick a definition which suits your needs. On the other hand, using simple criteria can occasionally break the model.
