A friend gave me a little book a few weeks ago with a startling title “Sum: Forty Tales From The Afterlives,” written by neuroscientist David Eagleman. My first thought was that it was about people who had come back from the dead, as there is a whole genre of such books today.

Thankfully, no, it is a collection of thought provoking essays from Dr. Eagelman’s remarkable, inventive mind. He imagines all of these different possibilities about what might happen after we die, imagined to make the reader think about the here and now — the miracle of the life we all have been given to live.

Without spoiling the entire book, my favorite tale of his is one where a person is given the chance to choose his next life. Do you want to be a king or queen or want to be rich and famous? It’s your choice. This particular person, who has had a difficult life, isn’t interested in money, fame, or “more” of anything. He wants simplicity.

 So, he chooses to come back as a horse. Why not? Grazing green pastures, frolicking over the hillsides, running across the plains without a care in the world, and doing all of this as a big, beautiful, literal stud. His decision is made, God speaks, and the transformation begins.

Eagleman writes: “A mat of strong hair erupts to cover you like a blanket … your neck thickens…your carotid arteries grow in diameter … your fingers blend hoof ward. Your concern about human affairs begins to slip away. But suddenly, for just a moment, you become aware of a problem you overlooked.

“The more you become like a horse, the more you forget what it was like to be a human wishing you could be a horse! And that’s not the worst of your revelation. You realize that, with your thick horse brain, you won’t have the capacity to ask to be a human again. Your choice to slide down the intelligence ladder is irreversible.”

Dr. Eagleman, observing the frail, troubled reality of being a human, then asks a rhetorical question. “What magnificent, extraterrestrial creature … would choose to become a human?” Implying of course, that no being of superior intelligence would ever stoop to become a lesser creature, to become one of us.

But that’s not quite right, not in light of the Advent story. Christians believe that the baby born and laid in the manger is more than a remarkable child, more than a religious symbol. We believe he is “Jesus Christ, God’s only Son,” as the Creed says, signaling that indeed, a “magnificent, extraterrestrial creature chose to become a human.”

Thus, Christmas is an event of descent, a movement of downward mobility, with heaven plummeting to earth, fusing these worlds together in a wondrous, inexplicable mystery. “Mild he lay his glory by,” and he came sliding down the ladder to reach, love, and elevate us. God met humanity on its own terms, becoming “what we are, that we might become what God is.”

Ronnie McBrayer is a syndicated columnist, blogger, speaker, and author of multiple books. Visit his website at www.ronniemcbrayer.org.