As an award-winning investigative reporter for the Chicago Tribune in the 1970s and ‘80s, Lee Strobel prided himself on being a skeptic who engaged in a rigorous search for the truth at all costs. He was also an avowed atheist — as a teenager he turned away from the Christian faith he was loosely raised with — and his wife Leslie had been an agnostic ever since they met at age 14.

When Leslie was jolted into exploring a relationship with God after a devoutly Christian nurse saved their young daughter from choking in a restaurant, Strobel lashed out by attempting to debunk Christianity via an investigative article that sought to disprove that the Resurrection had occurred. But the more he searched for evidence against that miracle, the more he found that there was, in fact, proof that Jesus had returned to life and truly was the unique Son of God.

Strobel’s resulting article was rejected by Tribune editors, leading him to instead write the book “The Case for Christ,” which took the world by storm in 1998, selling 14 million copies and counting. On April 7, a movie based on that book is being released by PureFlix Entertainment, the studio behind the hit Christian film “God’s Not Dead,” and Strobel hopes it can lead to even greater success in winning people over to Christianity.

“I think there are people who won’t read a book or come to church, but will see a movie because it’s well-done entertainment,” said Strobel. “I hope people who read the book will come as well, because it’s more than about the evidence, which the book focuses on, as the movie goes beyond that to a very human story. It’s a love story of two people who faced turmoil in their marriage — when my wife became a Christian — and how we overcame it, and doing it in the form of a movie and a story is very engaging to people.”

“The Case for Christ” makes Strobel’s story compelling by weaving together two different investigations: his search for evidence against the Resurrection, and his attempt to prove that a gang member named James Dixon shot a heroic cop and deserved to go to prison for the crime. Over the course of the film, Strobel discovers that both quests for the truth lead him in unexpected directions.

Strobel encounters a Catholic priest who shows him fragments from one of the earliest copies of the New Testament, noting that there are more than 5,000 ancient copies of the Bible found — four times as many copies as have been found of Homer’s “Iliad.” But particularly fascinating is his encounter with a physician who backs an American Medical Association study that explored the effects of crucifixion on the human body, showing that it was impossible to survive it under natural circumstances.

Throughout the movie, these quests are counterpointed by Lee’s efforts to tear Leslie away from her newfound faith and its effects on their marriage. Stars Mike Vogel (TV’s “Bates Motel” and “Under the Sun”) and Erika Christensen (TV’s “Parenthood”) provide an affecting center to the compelling film with these emotional moments.

“The first thing that came to my mind was divorce, because this wasn’t part of the plan. I saw conflict all the way to the horizon of our marriage,” said Strobel. “Now we’ll disagree how we spend our time, our money, how we raise our children and how our worldviews would clash. It prompted me to take my journalism and legal training to investigate and disprove and get her out of this cult.

“What’s interesting about Christianity is it’s one of the few world religions that invites investigation,” he continued. “It literally says that if the Resurrection is not an actual event in history, you’re justified in walking away from the faith. It challenges you to check it out yourself. We got on the same page again spiritually, restored our marriage and we’ve been married 44 years.”

The film also depicts the troubled relationship Strobel had with his father. When he tries to visit a psychiatrist (Faye Dunaway) to back his theory that the earliest Christian believers were merely victims of mass hysteria, she asks him about his relationship with his father because many of history’s most famous atheists, including Friedrich Nietzsche, Jean-Paul Sartre and Albert Camus, had strained relationships with their own fathers.

“When you have been disappointed with your earthly father, you don’t even want to know about a heavenly Father because it’d be worse with him,” said Strobel, who left journalism in 1987 to become a minister before embarking on his current career as a professor of Christian thought at Houston Baptist University. “I think there were some emotional issues and psychological issues that propelled me towards skepticism and atheism. Our earthly fathers really influence the direction we go spiritually. I think there’s a lot of moral, emotional issues that propel you towards atheism.”

Strobel has since written more than a dozen other books about the Christian faith and is optimistic about the state of Christianity in America today. He sees a true hunger in people for a strong spiritual foundation and feels that reports on declining church attendance miss the point.

“In the past, it wasn’t socially acceptable for people to say they’re not a Christian, and these days it’s more socially acceptable to just be honest,” said Strobel. “I think it’s good. Let’s not paper over who we are, let’s be honest and open. It’s something the church can then address. Let’s help them investigate and find answers, because, ultimately, they’re going to see that it’s Christianity that makes the most sense.”