In his book Reasonable Faith: Christian Truth and Apologetics, William Lane Craig observes how difficult it is for an atheist to live with the logical conclusions of his or her beliefs:

Unable to live in an impersonal universe in which everything is the product of blind chance, atheists sometimes begin to ascribe personality and motives to the physical processes themselves… For example, the brilliant Russian physicists Zeldovich and Novikov, in contemplating the properties of the universe, ask, why did "Nature" choose to create this sort of universe instead of another? "Nature" has obviously become a sort of God-substitute, filling the role and function of God. Francis Crick, halfway through his book The Origin of the Genetic Code, begins to spell nature with a capital N and elsewhere speaks of natural selection as being "clever" and as "thinking" what it will do. Sir Fred Hoyle, the English astronomer, attributes to the universe itself the qualities of God. For Carl Sagan the "Cosmos," which he always spelled with a capital letter, obviously fills the role of a God-substitute. Though these men profess not to believe in God, they smuggle in a God-substitute through the back door because they cannot bear to live in a universe in which everything is the chance result of impersonal forces.