Yes, admittedly, the Vietnamese claim that they're the most atheistic country in the world, and I'm sure North Korea could muster up some statistics to challenge the claim, BUT NEVERTHELESS…
According to GE2015, 24% of Finns identify positively as nonreligious (see Table 1). There has been some increase since 2011 (19%), when this option was introduced to the identification question. The percentage of religious identification was 36%. It is much smaller than Christian identification (67%), which most likely demonstrates that Finns consider themselves to be culturally Christian even when not regarding themselves as religious. Altogether 16% said that they were atheists.
[…]
Among those with only basic level education, 28% identify as nonreligious, whereas among those with tertiary-level education the figure is 23%.
[…]
For them, contrary to the older generations, being nonreligious or atheist has very little to do with the Soviet Union or Communism. At the same time, however, the historical filter that has connected Lutheranism and national identity explains (partly) why nonreligious identification is not more popular. In other words, the drift away from organic nationalism that combines ethnicity and religion towards the situation where national identity (or the idea of what it is to be an ordinary Finn) is divorced from religion advances the normalisation of nonreligious identities. At the same time, being religious is increasingly becoming a reflective choice rather than a taken-for-granted identification, as it should be in a scenario of weakening cultural Christianity.
So, we are led to suppose, the new Russophobia is not anti-atheist whereas the old Russophobia was precisely that: a sort of defensive Christianity erected as a barrier against Communism. This would be counterproductive, of course: Christianity leads to Communism in much the same way that Judaism leads to Christianity —Karl Marx is merely the author of another "new testament" —he offers neither an antithesis nor an antidote to the beliefs that came before.
Source:
https://www.tandfonline.com/doi/full/10.1080/13537903.2022.2138020#abstract


