The Orthodox countries in the region are further toward the east, and many were part of the Soviet Union.
The Catholic countries are further toward the west, and only Lithuania was part of the USSR.
Relatively few Orthodox or Catholic adults in Central and Eastern Europe say they regularly attend worship services, pray often or consider religion central to their lives. Three words, three distinct ways in which people connect (or don’t) to religion: Do they believe in a higher power? Do they feel part of a congregation, spiritual community or religious group?
For example, a median of just 10% of Orthodox Christians across the region say they go to church on a weekly basis. Research suggests that many people around the world engage with religion in at least one of these ways, but not necessarily all three.
Whether the return to religion in Orthodox-majority countries began before the fall of the Berlin Wall in 1989 remains an open question.
Reliable, verifiable data about religious beliefs and practices in the region’s then-communist regimes is difficult, if not impossible, to find.
In contrast with most of the former Soviet republics, respondents in Poland, Romania and Greece say their countries have become considerably religious in recent decades.
But these perceptions do not tell the entire story.
With few exceptions, in former Soviet republics the more common view is that those countries are more religious now than a few decades ago.
But Pew Research Center’s predecessor organization did ask about religion when it surveyed several countries in the region in 1991, during the waning months of the USSR.
In Russia, Ukraine and Bulgaria, far more people said they were religiously unaffiliated in 1991 than describe themselves that way in the new survey.
But, in some cases, even members of religious minority groups take this position.
For example, about a quarter of both Muslims and religiously unaffiliated people in Russia say it is important to be Russian Orthodox in order to be “truly Russian.” In addition, people living in predominantly Orthodox countries are more inclined than others in the region to say their culture “is superior to others” and to describe themselves as “very proud” of their national identity.