Reality exists because it is true, not because we believe in it. All that belief does is empower and inspire us to fight for mankind's destiny, in a secular future.

And of course. Any such idea would have foes who would prefer to remain lost in the darkness of ignorance, or pact with the dark things at the edges of reality. Corpse-whisperers and worshipers of fanes. Traitors to the truth, who valued their own ambitions over the good of Humanity.