Or, "lots of people believe X" is (when that's all you've got) strong evidence, but it can be broken down into sub-possibilities depending on how they come to believe X, and when you look at that in the case of (say) Christianity it turns out not to be very good evidence after all. (For instance, because most people who believe it turn out to believe it mostly because other people induced them to believe it when they were too young to think it through properly.)

(I think the contrary evidence would be plenty strong enough even if "lots of people believe it" were good evidence in this case, but it happens not to be.)