Overcoming division will be the easiest part. When technical progress brings us closer to a possible departure, I think the other major obstacle will actually be the considerable religious angst that will surely arise. Even though major religions aim at building “palaces in time,” they are all of this Earth, born in specific places with specific roots. In Ancient Greece, the Gods lived up on Mount Olympus. In Genesis, heaven is located in Eden, Mesopotamia. Moses lived between Egypt and the Promised Land, Jesus in Palestine, Mohammed in Arabia and Siddhārtha Gautama in Nepal. Can we take God, or rather our gods, up into space? If we settle on another Earth, will we build churches, synagogues, temples and mosques? Will the men and women who colonize other worlds come back to Earth as a pilgrimage? Will they look toward the Blue Planet as they say their prayers? No major religion appears to clearly mention any other worlds, inhabited or not, but there is nothing that would a priori oppose the concept of uprooting them and transferring them to another planet. At least not in theory, for in the majority of humankind's inner faith, at least as I perceived it when growing up, man is the only subject of Creation and Earth his only home.

Indeed, the Catholic education I received was a perfect reflection of how science had described the Big Bang, this monumental fiat lux that had provided the prologue to Creation itself. Without knowing it at the time, I was a concordist, in the same way that Pope Pius XII had viewed the burgeoning theory of the Big Bang, as initially developed by Abbot Georges Lemaître in the 1930s, as a scientific confirmation of the story portrayed in Genesis. In every scientific discovery, I only ever saw reaffirmed proof of the existence of God and, furthermore, His project to make humankind the ultimate and exclusive goal within the universe. For instance, I perceived the extinction of the dinosaurs as a guided quirk of fate, because had the killer meteorite been just a little bigger, smaller life-forms would have been wiped out along with the bigger reptiles and mammals would not have been able to evolve and give birth to human beings—like Goldilocks's final chair, it was just the right size to enable them to rise up from the Jurassic swamp.