Most Nonreligious countries

I wouldn't say North Korea is an irreligious country. Its state cult may be officially secular, but it has doctrine, mythology, worship, pilgrimage and many other elements of a religion: It is an official state doctrine that "the Great Leader is a flawless and incorruptible being who never commits mistakes, who is always benevolent and who always rules for the masses." The North Korean constitution describes their "holy mountain", Mt. Paektu, as "the sacred mountain of the revolution", and North Korean media celebrates natural phenomena witnessed at the mountain as "portentous". Many North Koreans make a pilgrimage to this mountain, which is also the former headquarters of their "Great Leader", who regularly and demonstratively rides up the mountain on horseback: https://www.bbc.com/news/world-asia-50655693

I'd say if the deification of the Roman emperor was a religion, this is one as well.

And NZ for New Zealand, as other quizzes.