In "Touched by Jesus?" airing tonight, the National Geographic Channel uses forensic technology and dating methods to explore some of religion's most contested claims.
For the Doubting Thomas' among us, the network probes the deepest controversies of Christianity, with the help of carbon dating, fiber analysis and laboratory tests.
Can believers replicate the wounds of Jesus' crucifixion with spontaneous bleeding, or stigmata? Did the Shroud of Turin actually wrap the dead body of Jesus Christ? Did Jesus marry Mary Magdalene and have children?
Here is a taste of what the program has to offer:
Since the Middle Ages, there have been about 300 reports from all over the world of people claiming that, spontaneously, the wounds of Jesus Christ appear on their hands, feet and head. About 20 percent have been canonized by the Catholic Church, National Geographic said.
One minute they may be fine, the next, they say they feel the pain of Christ's crucifixion and manifest the corresponding markings
St. Francis of Assisi was not only the first and most famous stigmatic, but the only one to have been officially sanctioned by the Church with a paper declaration of authenticity.
While skeptics may find that suspicious, the Church has another explanation.
"That doesn't mean we haven't had other cases of stigmata, it means that it is really very difficult. So if there is no real need for a declaration of authenticity, the Church will not go into it," Monsignor Charles Scicluna, the Holy See in Vatican City, says in the National Geographic program. "In cases where the person is still alive, the instinctive reaction of the Church is to hide the phenomenon is to suggest silence, modesty and also to leave it to its natural course."
Still, skeptics maintain that the stigmatics are pulling the wool over onlookers' eyes.
"The whole concept of stigmata is interesting if we just step back and look at the broad picture. It looks more like a magic trick or some cheap demonstration. Some pseudo show-bizzy miracle that's just not convincing," says Joe Nickell, a paranormal investigator for the Skeptical Inquirer Magazine.
But others argue that science still has not fully explained the phenomenon.
"It defies science," Mario Martinez, a church-approved clinical psychologist, told National Geographic. He has studied several stigmata cases and uses a series of blood tests and mental examinations to try to authenticate them.
After meeting with the alleged stigmatic, Martinez takes a blood sample and sends it to a lab for testing. At the lab, the liquid is tested to make sure that it is indeed blood and that it is the alleged stigmatic's blood. The tests can also indicate if there are elevated stress levels or immune cells.
"An authentic stigmatic is one who has the wounds that cannot be explained biologically," he said.
Skeptics, however, question why the bodies of dead stigmatics never show the wounds that they claimed to have lived with.
And they question the motivation. Some, they say, use their "gift" to make money, while others may see it as a way to renew faith among onlookers.
Skeptics also point out that experiments have shown that it's easy enough to self-inflict with razors or even chemicals that leave a wound-like marking on the skin or produce a blood-like liquid.