One out of five non-Christians in North America doesn't know any Christians.

That's not in the fake-Gandhi-quote "I would become a Christian, if I ever met one" sense.

It's new research in Gordon-Conwell's Center for the Study of Global Christianity's Christianity in its Global Context, 1970-2020. Missiologist Todd M. Johnson and his team found that 20 percent of non-Christians in North America really do not "personally know" any Christians.

That's 13,447,000 people—about the population of metropolitan Los Angeles or Istanbul—most of them in the United States.

And that number includes atheists and agnostics, many of whom are former Christians themselves and more likely to have close Christian contacts. Without that group, 60 percent of the non-Christian population has no relationships with Christians.

Worldwide, the numbers are much worse: more than 8 in 10 non-Christians do not personally know a Christian. But Christians only make up a third of the world's population. The United States, meanwhile, ranks in the top 10 Christian countries, with 80 percent of the population identifying as Christians.

The biggest factor in explaining why so many North American non-Christians don't know Christians is immigration, Johnson said. The U.S. attracts more Buddhist, atheist, and agnostic immigrants than any other country in the world. It ranks second for Hindu and Jewish immigrants, and seventh for Muslim immigrants.

But immigrants are also keeping the percentage of those who don't know a Christian from going higher. That's because the U.S. also attracts more Christian immigrants than any other country. And the region that sends the most immigrants ...

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