An evangelical Christian relief organization on Sunday began setting up a massive field hospital in Central Park to help New York City cope with the crush of patients sickened by the deadly coronavirus.

Samaritan’s Purse — which is led by Franklin Graham, son of the late televangelist Billy Graham — trucked in four trailers of gear, including tents, beds, personal protective equipment and 10 ventilators for the most seriously ill.

A team of 70 health care workers from around the US will be led by Dr. Elliott Tenpenny, who’s previously treated Ebola patients in West Africa, Syrian refugees in Iraq and earthquake victims in Ecuador.

“This is honestly the most improbable place we’ve ever been,” he told The Post.

“I never would have guessed we’d come to New York City with something like this. But New York never thought it would be dealing with a pandemic, either.”

At 8 a.m., 20 volunteers from the Big Apple helped 50 Samaritan’s Purse employees set up the first of what will be 14 tents covering 50,000 square feet of the park’s East Meadow.

By mid-afternoon, three had been erected.

The tents will accommodate 68 patients, including 10 in makeshift intensive care units that will have a ventilator for each patient.

Round-the-clock construction is expected to take a total 48 hours, with the hospital set to open on Tuesday morning.

The city provided logistical support and coordination, and also expedited an emergency work order to permit the work on public property, a spokeswoman for Mayor Bill de Blasio said.

The field hospital will not take walk-ins, but will instead treat patients transferred there by the Mount Sinai hospital network, including its nearby, flagship hospital on Fifth Avenue.

Another of the system’s hospitals, Mount Sinai West, came under fire last week when The Post published a front-page photo that showed three of its nurses wearing garbage bags to protect themselves from the coronavirus.

A nursing manager at Mount Sinai West, Kious Kelly, also died of the disease on Tuesday, with his sister telling The Post she “absolutely” believed he was infected there.

Mount Sinai didn’t immediately return a request for comment.