For years Dr. Eben Alexander III had dismissed near-death revelations of God and heaven as explainable by the hard wiring of the human brain. He was, after all, a neurosurgeon with sophisticated medical training.

But then in 2008 Dr. Alexander contracted bacterial meningitis. The deadly infection soaked his brain and sent him into a deep coma.

During that week, as life slipped away, he now says, he was living intensely in his mind. He was reborn into a primitive mucky Jell-o-like substance and then guided by “a beautiful girl with high cheekbones and deep blue eyes” on the wings of a butterfly to an “immense void” that is both “pitch black” and “brimming with light” coming from an “orb” that interprets for an all-loving God.

Dr. Alexander, 58, was so changed by the experience that he felt compelled to write a book, “Proof of Heaven,” that recounts his experience. He knew full well that he was gambling his professional reputation by writing it, but his hope is that his expertise will be enough to persuade skeptics, particularly medical skeptics, as he used to be, to open their minds to an afterworld.