The 10 most religious countries in the world

If religion is the opiate of the masses, these countries know how to get high.

According to data from the 2017 Best Countries rankings – a characterization of 80 countries based on a survey of more than 21,000 global citizens – Saudi Arabia is perceived to be the most religious country in the world.

The largest nation in the Middle East, ranking No. 9 among the world's most powerful countries, is a theocratic monarchy with a legal system based on Islamic Shariah law, where citizens can receive harsh punishments, including death, for apostasy and blasphemy.

Since 2004, Saudi Arabia has been designated as a "Country of Particular Concern" under the International Religious Freedom Act of 1998 for participating in "severe violations of religious freedom," according the U.S. Department of State's International Religious Freedom Report for 2015.

Data shows Islam is spreading, on track to surpass Christianity as the world's biggest religion. While the world's population is projected to grow 32 percent in the next few decades, the number of Muslims is expected to increase by 70 percent – from 1.8 billion in 2015 to nearly 3 billion in 2060, a recent Pew Research Center report shows.

Meanwhile, the Jewish homeland of Israel comes in second for its perceived religiosity – though the actual devoutness of its population is up for debate.

About 65 percent of Israelis report being either not religious or convinced atheists, compared to 30 percent who say they are religious, according to a 2015 report from WIN/Gallup International.