There was an article published last October on CNN's website, about an after death experience of a mother of two in suburban
Boston. It has some relevance as background to Shade's own
after death experience, or Mrs. Z's:
"It was very peaceful and light and beautiful. And I remember like, when you see someone you haven't seen in a while, you want to hug them, and I remember trying to reach out to my ex-husband, and he would not take my hand. And then they floated away." Next, she says, she was overwhelmed by "massive energy, powerful, very powerful energy." "When that was happening, there were pictures of my son and my daughter and my granddaughter, and every second, their pictures flashed in my mind, and then I came back."
According to the Near Death Experience Research Foundation, nearly 800 near-death experiences happen every day in the United States.
The article reprises in greater detail the debate Shade and the Doctor have in Canto 3 concerning the authenticity of the experience.
Given the emotional reaction people commonly have to such experiences they can probably be assumed to be one of the wellsprings of religion.