Here’s how to completely misunderstand the significance of there being a multiplicity of religious beliefs, and how to avoid that misunderstanding.
Inference from Inconsistencies in Belief
Atheists often argue that there can be no God because there are so many different religious traditions saying inconsistent things about the nature of God. One could argue the point that it is improbable that people would so variously perceive the attributes of God, if there were a God. But the counter to that is simply that it is improbable that there would be a near-universal perception of some sort of God or god, if there were no God.
Obfuscation of the Question
So the atheist argument can be amped up, in a way, by feeding the data through a distorting analysis. Evidence such as the variation in religious belief can be put through a complicating analysis so that it seems to create the opposite of the obvious inference. This is a sophisticated way of putting one’s thumb on the scale, in favor of atheism. The critique is sometimes made applying Bayesian probability analysis, whereby one starts with a probability assigned to a proposition (a prior “credence”) and then adjusts that credence as more evidence is obtained. The Bayes theorem is valid, but as with so much else, garbage in yields garbage out.
If all religious texts and traditions were in agreement on the nature of God, then that might be considered strong evidence for the God proposition. It would mean that God consistently reveals Himself to people. Therefore, one’s prior credence in favor of the God proposition would be enhanced by this bit of evidence.
Of course, all religious texts and traditions do not reveal God’s nature, because they’re irreconcilably inconsistent with one another. Therefore, one could infer that tenets of religious belief are man-made, not God-made. Therefore, one could further argue, the prior credence attached to the God proposition should be diminished. In this way, an atheist can use what appears to be a sound mathematical model to try to explain why there is almost certainly no God.
But that would be wrong, and here are fundamental reasons why.
The Right Proposition
First, one must be sure of examining the right proposition. The proposition under examination—whether there is a God—does not lend itself to the Bayesian analysis at all, if one does not consider also the correct opposing proposition. The opposing proposition cannot be simply that there is no God. That would just be a negation of the first proposition. The competing ideas are that there is a God who created everything and remains involved with His creation, on the one hand; and that all of matter is self-generated and able to acquire greater complexity without outside influence, on the other.
One games the system by merely juxtaposing a proposition with a negation of that same proposition. Applying the Bayesian analysis, if one sets up the competing propositions as “God” and “not-God,” then the “not-God” credence must necessarily be the reciprocal of the “God” credence. Let’s say you start with a 25% prior credence for the existence of God. That necessarily means that you have a 75% prior credence for there being no God. The “not-God” proposition is merely derivative of the “God” proposition. If you decide that the inconsistencies among religions diminishes the probability of there being a God, then you automatically enhance the not-God proposition, and by the same amount.
The competing belief to the God proposition is not “not-God,” but materialism (or naturalism, or atheism, take your pick). The propositions should be competing propositions about ultimate reality: (a) that there is a God active in the world; or (b) that all of reality is physical and self-created and self-sustaining. The opposite of the God proposition is not merely that there is no God, but rather that all of reality is explained by physical things in motion, only. One’s prior credence in that proposition is not merely the reciprocal of the God proposition, and in fact may be less than the God proposition.
The Evidence Added to Prior Credence
Second, one must correctly understand the new evidence presented. The evidence is not merely inconsistency in religious belief. To be complete, one must also take into account the near-universal presence of belief, consistent or otherwise.
If we understand the evidence in this way, we’re not likely to be misled into looking at only the less consequential part of the evidence. We’re less likely to be misled into comparing inconsistent belief with hypothetical consistent belief. Instead, we will compare the near-ubiquity of religious belief, with hypothetical absence of belief.
The evidence might point more strongly toward God’s existence, if religions were consistent in their beliefs about Him, certainly. But the ubiquity of some sort of religious belief is stronger in favor of the God proposition, than its inconsistency is against it.
Put in simple, non-Bayesian terms, the headline is not that there are so many inconsistent beliefs about God. The headline is the near-universality of belief in God. The same piece of evidence—the ubiquity of inconsistent beliefs—should enhance the God proposition, not diminish it.