Here's a question, do you believe in heaven? Various polls find that somewhere around 80% of americans do. But a harvard-trained brain surgeon wasn't so sure until he spent a week in a coma and came... See More
Here's a question, do you believe in heaven? Various polls find that somewhere around 80% of americans do. But a harvard-trained brain surgeon wasn't so sure until he spent a week in a coma and came out with an incredi description of the afterlife. My co-an chore terry moran has the story. Reporter: A mild afternoon in lynchburg, virginia and eben and holly alexander are at a high school soccer camp cheering on their son. They are a perfectly ordinary family with an extraordinary story. They have been touched by a medical miracle and maybe more. I mean, it was impossible after impossible after impossible. Reporter: Eben alexander, a harvard-trained neurosurgeon who was a skeptic when came to religion survived a near-death experience and he now carries the memory of what he says was a journey to heaven. A journey that all his scientific training cannot explain. ON NOVEMBER 10th, 2008 EBEN Awoke with a searing headache. When his wife holly checked in on him he was having a tremendous seizure. I said, say something. He didn't say anything so i called 911. Reporter: Eben was rushed to the hospital. The only word woe could truly make out was help and the rest of his verbalization was purely screaming. Reporter: He had been stricken with an extremely rare and virulent e. Coli meningitis infection that was raf rajjing his brain plunging him into a coma. I mean, I was trying to die. Reporter: In fact, doctors gave him almost no chance to live and told his family if he did survive he'd be brain damaged for the rest of his life. His eyes were just off and cocked. Just like no one was there. Reporter: Eben believes holly is right. He wasn't there. Did you go to heaven? Yes. In every sense of the word that's what my -- what my experience showed me. Reporter: His first recollection, he says, was being a speck of pure awareness in a dark and murky underworld. And then I was rescued by this beautiful spinning white light that had a melody, indescribably beautiful melody with it that opened up into a bright valley, just an incredible rich ultra real world of indescribable complexity. Reporter: God was there, he says, and he encountered him through an orb of brilliant light. He soared on the wing of a butterfly with a beautiful young woman as his companion and the young woman gave him a message to take back from heaven. Re loved. You are cherished. There's nothing you have to fe there's nothing you can do wrong. Reporter: It's a beautiful vision, but heaven? A lot of people are going to say, doctor, it was a hallucination. Your brain got zapped by this disease, all the wires got crossed and you saw a girl on a butterfly wing and you were spinning up in a melody. I know this was not a hallucination, not air dream, not what we call a confabulation and I know it occurred outside my brain. Reporter: But how? How can he even suggest that much less claim it's proof of heaven as he called his new book. He showed us his brain scan. It wasn't leaving any part of my -- of it unaffected. Reporter: Your conclusion is because all of this outer area which is the higher functioning was covered with the inn, what you experienced in the coma wasn't part of the brain? Right. Reporter: Many neu neuroscientists are deeply skeptical arguing his brain must have produced his vision somehow most likely as he came out of coma but something else happened. After he recovered, eben who was adopted saw a picture of his sister from his biological family who died years ago, a woman he never knew. I knew who my guardian angel was on the butterfly wing. It was the most profound experience I've ever had in this life. Reporter: Your sister by birth and from a family that you didn't know because you were adopted who died several years ago who you had never met, you saw while you were in coma? Yes. And that was the key. That explained everything. Reporter: Dinnertime at the alexander home. Jesus, bless these -- Reporter: They were not a particularly religious family before eben's coma. He was a skeptic. Not anymore. This proves that our soul, our consciousness, our spirit doesn't depend on the existence of the brain and body at all, and easily is actually freed up to a much higher state of knowing when it's freed from this body.
This transcript has been automatically generated and may not be 100% accurate.