OSLO (AP) ― It may sound like an unlikely No. 1 best-seller for any country, but in Norway ― one of the most secular nations in an increasingly godless Europe ― the runaway popularity of the Bible has caught the country by surprise. The Scriptures, in a new Norwegian language version, even outpaced “Fifty Shades of Grey’’ to become Norway’s best-selling book.

The sudden burst of interest in God’s word has also spread to the stage, with a six-hour play called “Bibelen,’’ Norwegian for “the Bible,’’ drawing 16,000 people in a three-month run that recently ended at one of Oslo’s most prominent theaters.

Officials of the Lutheran Church of Norway have stopped short of calling it a spiritual awakening, but they see the newfound interest in the Bible as proof that it still resonates in a country where only 1 percent of the 5 million residents regularly attends church.

“Thoughts and images from the Bible still have an impact on how we experience reality,’’ said Karl Ove Knausgaard, one of several famous Norwegian authors enlisted to help with the translation.

Scholars aren’t surprised at the success of the plays or the new Bible translation, explaining that faith is a deeply personal matter in this nation of taciturn Scandinavians who regularly withdraw from city life to spend holidays at remote cottages in the solitude of the mountains, fjords and forests.

“Church attendance is a poor measure of the Norwegian state of faith,’’ said post-doctoral fellow Thorgeir Kolshus at the University of Oslo. “Religion is a very private thing for Norwegians.’’

Anne Veiteberg, publishing director of Norway’s Bible Society, said that increased immigration also probably has been a factor.

More than 258,000 immigrants have settled in the country during the last six years alone, adding diversity of race and religion. The Church of Norway estimates that around 60 percent of immigrants are Christian, while the rest are Muslim, Buddhist or Hindu.

“Now that we’re exposed to other faiths, Norwegians have gotten more interested in their own faith,’’ Veiteberg said.

Released in October 2011 by the Norwegian Bible Society, the new translation replaces a 1978 edition, with the goal of improving readability and accuracy. For example, in the older version, Mary was called a “virgin.’’ In the new translation she is referred to instead as a “young’’ woman. The U.S. Conference of Catholic Bishops also made this change in its latest Bible translation from 2011, saying the change didn’t alter teaching about Mary, but was meant to address the possible different meanings of the Hebrew word “almah’’ in the text.

Norway’s Bible Society promoted the new translation like a pop fiction novel, stirring anticipation by giving out teasers of biblical stories before its release.