As many as one in five churches may shutter completely because of the fallout from Covid-19, the president of prestigious Christian research organization, Barna Group, predicts.

David Kinnaman told NPR that churches had been coping well with the pandemic in the early stages, but things have become increasingly tougher. 

One of the challenges for churches is that even though restrictions have eased and services are resuming, the people are staying away. 

For some churches "a lot less people are coming" now than before lockdown and that's an indication, for Kinnaman at least, of weak personal relationships.  

"They're recognizing that the relationships that they thought were much deeper with people were actually not as deep as they expected," he said. 

Kinnaman said the data from a couple of months was already suggesting that one in five churches at the least would permanently close because of Covid-19.  Now he thinks the figure is likely to be even higher. 

That's because the numbers are down, not only in the pews but in the books, and it will take more than re-opening churches to fix that, he believes.

"The disruptions related to giving, and maybe even as important to all that, is that even for those churches that have reopened, they're seeing much smaller numbers of people show up," Kinnaman said.

"So simply reopening a church doesn't fix the underlying economic challenges that you might have."

According to Kinnaman, more pastors are concerned about their survival now than they were early on in the pandemic.  At the start of the outbreak, Barna research found that 70% of pastors were "very confident" about their church's survival, but as the crisis has progressed, that figure has fallen to 58%. 

In the long term, Kinnaman thinks the pandemic will prove to be a moment of "fundamental change" for the American church, ushering in more online participation. 

"Obviously, there will be a lot more online attendance than ever before, even after all churches reopen. I think this digital church is here to stay," he continued.

"I think also it's really going to change the way people think about their donation relationship with local churches as well.

"There'll have to be even greater demonstration of the value that a church brings not just to those who attend but also those who are part of this community."