But what of those who do not think God is merely a metaphor, would buying the book not be akin to Trumpetts and Trumpeteers buying a self written book by Trump on his political views? In other words how would it matter, if only those who thinkGod is only a metaphore would buy the book? But on second thought, people who already think this would no need for further convincing.
Course it costing only only a buck, they could take a chance on it.
However I may be unnecessarily unkind here, so,if I am not reading you correctly, forgive my style.