It was a chilly winter morning when 14-year-old John Smith fell through an icy Missouri lake. When emergency workers finally pulled him out, he'd been submerged under the frigid water for 15 minutes.

At the hospital, John lay without a heartbeat for more than 60 minutes.

"After I entered his room, I put my hands on his feet, and they were cold and grey, and I just knew he was gone," John's mother, Joyce Smith, told The Gospel Herald in an exclusive interview. "I began praying out loud, begging God for my son's life, and calling on the Holy Spirit, saying, 'Please give me back my son.'"

And then, something miraculous happened.

As soon as Joyce prayed over her son, his pulse immediately returned, astounding the nurses and doctors around him.

"The nurse had her finger on John's pulse for 27 minutes, and had gotten nothing," Joyce said. "She told me, 'The minute you prayed, something moved up John's body with such force, it pushed me back -- and suddenly, I got a pulse.' They were stunned."

The Smith's incredible story of healing and restoration is the subject of Joyce's book, "The Impossible." A film is also in development through 20th Century Fox, by Executive Producer DeVon Franklin (Heaven is for Real, Miracles from Heaven). Titled "Breakthrough," the film slated for 2019 release stars actress Chrissy Metz ("This Is Us") as Joyce, while John is played by Marcel Ruiz ("One Day at a Time").

"My family isn't publicizing this story for our benefit," John told GH. "We're doing this because our country needs hope. We're not the answer -- God's the answer. We're just sharing the story so this country will see how great our God is. He's not dead, He's alive, and He's still in the miracle working business. I'm blown away by how great He is."

Three years later, John remembers little about the accident. He, along with two friends, Josh Sander and Josh Rieger, were "messing around" at a local park when the ice on Lake Sainte Louise cracked, and the three friends plunged into the 40-degree water.

"In the moment, we all knew that the possibility of the three of us dying was very real," Josh told GH. "Me and Josh were about 50 feet out from the dock, and Josh was screaming, 'I don't want to die.' I was screaming, 'Call 911!' Sander rescued himself, and I was able to push Rieger above water, saving his life."

John, however, wasn't so fortunate.

"I got the phone call, hearing my son had been in a terrible accident," Joyce shared. "It's the one phone call every parent dreads. I don't even remember how I got to the hospital -- I was praying, begging God to spare my son. We waited 17 years to have him; we adopted him from Guatemala. I just couldn't believe that God would take our son after all we'd gone through. God, in his grace and mercy, ended up getting me to the hospital in one piece."

When Joyce got to the hospital, the medical team had been performing CPR for almost a half-hour with no success.

"When I walked into the room, I didn't realize they were about to call time of death," she recalled.

Shortly before the accident, Joyce had been participating in the Believing God Bible study by Beth Moore, which hinges on the statement that "I believe God is who He says He is, and I believe He can do what He says He can do."

"I don't believe it was a coincidence," Joyce said. "When I walked into the ER, I was of the mindset that God was there, and He was going to be with us through this."

After her son's pulse returned, Joyce thought the worst was over -- but doctors disagreed.

"The doctor told me, 'Even if John lives, he'll be a vegetable. There's brain damage, and the only brain function is brain stem function and it's very rudimentary,'" she said. "I told him, "Do your best. God will do the rest, but I want no negatives to be spoken around him. When you are in the room, I only want him to hear positive things."

Two days later, John woke up and began communicating with those around him. Seven days after waking, John went off the ventilator, and 16 days later, he walked out of the hospital, basketball in hand. His rapid recovery defied every expert, every case history, and every scientific prediction.

"To this day, John has not had any side effects from the accident, despite doctors' predictions," Joyce said. "God has totally and completely healed him. He carries a 3.0 in high school, he went back to play basketball, and at one game he scored 30 points. God has been so miraculous and good in all the things that He has done."

To a watching world, John and Joyce Smith hope their miraculous story proves the power of prayer, the goodness and nearness of God, and that with faith, nothing is impossible.

"We've had so many people come up and say, 'This story has changed my life and restored my faith in God,'" Joyce said. "That's what we hope people take away from our story, that it draws everyone who hears it closer to God."

Watch the trailer for the upcoming film, "Breakthrough" below.