I Was Wrong About Christianity

When Does A Theory Entailing Some Unlikely Result Lower Its Probability?

Suppose my friend Todd is pretty trustworthy. He tells me the result of 100 coin-flips (heads, tails, tails, heads, etc). I think I have reason to believe him, with him being relatively trustworthy. But here’s an argument for why I shouldn’t: he just told me that some extremely improbable event occurred. The odds that a series of coins would come up in some specific order are 1/2^100. Normally, if someone tells me that an event occurred with a prior probability of 1/1,267,650,600,228,229,401,496,703,205,376, I don’t believe them. That’s why I typically don’t believe people when they tell me that they won the lottery ten consecutive times.

This argument goes wrong, however, because, while the odds of that event occurring are near zero, the odds that someone would falsely report that event are also near zero. If a person was making up some sequence of coin flips, it would be absurdly unlikely that they’d fabricate that particular random sequence—the odds are even lower than 1/1,267,650,600,228,229,401,496,703,205,376.

So in other words, it’s not that some theory predicts the improbable things happened that makes it unlikely. Improbable things happen a lot. Instead it’s the theory predicting improbable things, such that the evidence for those things is better explained by some alternative hypothesis. With this in mind, we can see why much of my case against Christianity was based on an error. In my case against Christianity, I argued that Christianity required believing lots of other improbable things. But with this insight in mind, my case against Christianity begins to look weaker. I don’t think this core insight considerably undercuts the core evidentiary force of either of the first two claims that a Christian is committed to: that God exists and he’d intervene in the natural world. It does undercut the third point, however:

God would become incarnate in 1st-century Roman Palestine, giving some rather strange teachings, including condemning the practice of handwashing as pompous and pretentious.

The point about becoming incarnate in first-century Roman Palestine is mostly a red herring. It’s true that it’s intrinsically unlikely that God would become incarnate in first-century Roman Palestine, but it’s also unlikely that the Christians would say he became incarnate in such a place if he hadn’t. This is basically a wash.

Now, the fact that Jesus gives some strange teachings still has some force. One would expect God to give correct teachings. Still, the one about handwashing doesn’t have much force—if you think Jesus wasn’t omniscient while incarnate then you should think that he was ignorant of, for instance, the germ theory of disease. Now, it might be a puzzle why Jesus would come to Earth with sort of limited powers to excise demons but that’s a single thing you need to posit which explains most of Jesus’s weird teachings.

The fourth Christian posit that I listed was:

The way he’d make his teachings known would be by enabling humans to write books after the fact. Strangely, rather than getting people to write about this early, commanding them to write down his resurrection quickly, the first writings would be decades after the fact. The evidence would thus not be overwhelming—the way one would come to him who was not steeped in a Christian upbringing would be by inference to the best explanation of several historical facts which, while somewhat well-attested, are not beyond dispute. This is a rather curious way to make himself known.

I think this one might be a wash as well. It’s true that it’s a bit surprising that the Christian texts were compiled decades after the fact. But on the non-Christian story, it’s surprising that they weren’t compiled later. The first Buddhist texts were compiled hundreds of years after the Buddha’s death, as were the first recordings of the Sinai events. In ancient history, it’s common for the first texts about some event to be compiled hundreds of years after the event—e.g. the existence of Alexander the Great.

Furthermore, I think a Christian can tell a plausible story about why the evidence isn’t better. God wants us to have some uncertainty so that there’s room for faith. If the evidence for the resurrection were totally overwhelming, that might be bad news for our long term relationship with God. Perhaps it’s especially valuable for humans to spend time in a state of uncertainty, hoping that Jesus is divine. The next few things on the list, I think, have similar force to what I earlier believed. But my last objection, that Christianity requires a trinity which we should doubt exists, I think actually backfires.

It’s true that the odds that God would be a trinity are low. But the odds that 1st-century people in Roman Palestine would have views that indicate a trinity are similarly low. It’s such a weird and specific doctrine, it’s not the type of thing they'd be expected to falsely assert. So, therefore, this might mean that trinitarian considerations wash out.

Furthermore, I’ve become more sympathetic to the coherence of the trinity. I think that every possible arrangement of fundamental things forms a composite object. For example, there’s a composite object composed of me, your mom, and the Empire State Building. This is a view called mereological universalism that I’ll perhaps discuss at more length in the future, but it’s a pretty popular view of mereology. This can make sense of the trinity: there’s one composite object, called God, composed of the three divine persons.

Ultimately, I still think Christianity is probably false. But I’m less confident in that than I used to be, before realizing that several of my arguments were bad.