As a high school student I was deeply in doubt about my Christianity (as is probably evident from my blog posts to date). In the course of investigating my beliefs and finding all of the apologetics unconvincing, I started to wonder how I could determine whether anything in the Bible was actually true. Not assertions that “it’s the Word of God” or just “have faith” or any similar platitudes–how could I really know?

When I entered college and had some freshman philosophy tools to help frame this question a little better, this because an issue of both ontology (what is real) and epistemology (how do we know). Those are both very weighty issues in their own right but I’m using those terms now to help draw a distinction. It is, then, possible that a god does exist–and, again, atheism is not necessarily a position that a god must not exist–but we may not be able to know it. The deist god, for example–one who started the universe in motion but is not involved in anything past the moment of creation–is an unfalsifiable premise. Could that god exist? Certainly, but it would be indistinguishable now from a universe in which no god existed. How could we ever know whether such a god existed or not?

This is really an epistemological question. How could we know that any god (or anything supernatural for that matter) exists? Well, there are several main arguments that have been used for millennia:

1. Logical arguments for god
2. Experiential arguments for god
3. Evidence for god

The logical arguments for god have been proposed, debated, refined, and re-proposed since ancient times and all of them rely on some premise that cannot be logically sound. For example, Aquinas (and many others) assert that the universe must have a cause and therefore an uncaused cause (or unmoved mover, or first cause, or any number of other functionally identical terms). The obvious problem here is that we do not know that the universe must have had a cause. We may intuit that it should as the idea of anything either eternally existing or an effect happening without a cause are both difficult, if not impossible, for humans to comprehend. Of course, this merely begs the question of “what created god?” and any answer to this is purely an assertion. The claim that God is an exception to all caused things needing a first cause is merely a special pleading fallacy. If an apologist says that god is “defined” as causeless and eternal then that is simply begging the question.

I won’t go into detail on the various logical arguments here such as the cosmological, ontological, or teleological arguments for god (although I might in future posts) because they all include some form of fallacy or unfalsifiable assertion in the premises.

Experiential arguments for god are actually far more common. Perhaps the most common reason that I have personally heard for why individuals believe. They have “seen the power of prayer” or “felt the Holy Spirit” or “seen God work in the world.” There are two critical problems with experiential arguments. The first is that, to borrow from Thomas Paine, all revelation is necessarily first-person–to everyone else, it’s hearsay. It is crucial to note here that just because something is hearsay does not mean it is not true–it just means that it cannot be convincing for someone else who did not experience it.

The second problem (and more to the point for my experiences) is that while you may experience something that you attribute to god–how could you possibly rule out any other explanation? How did you determine that a feeling of euphoria you had in church was the actually the Holy Spirit? Is it because you were in church? Is it because people around you told you that it was? Why isn’t a negative feeling in church automatically associated the same way? Wouldn’t it be ridiculous to assert that your having a headache or feeling gassy was the spirit just because it happened in church? What possible experiment could you conduct or epistemological framework could you use to actually know that an experience was supernatural instead of just feeling that it was?

The last kind of argument is one that claims to be “evidence for God.” There are really two main issues here. Either, the “evidence” put forward for a god claim simply isn’t true or it is used in a fallacious way. Let me clear, when I say fallacious here I am not saying that someone is intentionally lying (it is not necessary to make motivational claims in any case) but rather that the use of evidence in these cases is part of a logical fallacy.

You can find any number of articles, videos, books, and other media claiming to have “evidence” or “proof” of God. Sometimes these claims are simply false, as I alluded to above. Young Earth Creationists (YECs) tend to most often make factually incorrect claims such as “the Grand Canyon was carved in a single day by Noah’s flood” or “fossil layers are caused by ‘hydrological sorting’ not by deposition of sediment over time. These are simply not evidence because they are false and demonstrably so.

The remainder of the “evidence” for god most often falls into arguments from personal incredulity. The fine-tuning argument, the abiogenesis argument, and so on all boil down to “I/we don’t understand this, therefore god.”

This is the reason that many atheists take the shorthand approach of saying “there is no evidence that a god or gods exist” when what most of them really mean is “there is no evidence sufficient to make a valid and sound argument for god that should be convincing to all rational people.”