The second pillar of my atheistic treatise is the one I called “via metaphysics”. Of the three, it is probably most applicable to the religious beliefs that fall into the pantheistic genre, like those held by Spinoza and Einstein. This framing of religion and god is popular among scientists and other empirically-minded people since it does not suffer from the lack of concrete evidence for more traditional religious beliefs. However, the fact that it does not suffer for a lack of evidence in fact reveals a different flaw, in that it does not pay rent.
Another useful way of approaching this argument is through Carl Sagan’s analogy of The Dragon in My Garage; this hypothetical discussion conveniently parallels the way more traditional religious believers might behave when challenged on the metaphysical implications of their beliefs.
Now these two links on their own give a pretty good in-depth explanation, so I suppose I could just leave it at that. But that would make this a short and boring post, so I’m going to state my own “plain” version of the central claim without any fancy analogies, just to be clear:
If a belief has no practical implications or observable results, in other words if it does not change what we expect to happen in the universe, then that belief is useless.
The second half of the argument is the much simpler claim that useless beliefs, in this sense, are false for all intents and purposes. More practically, their truth-or-falsiness literally by definition doesn’t matter. Since there are an infinity of such possible beliefs (just start with Sagan’s dragon in all shapes and sizes; why couldn’t they overlap?) and we have no way to distinguish between which ones might be true or false, the alternative to discarding the entire category is to go mad trying to accommodate an infinity of contradictory beliefs. The only reasonable solution is to discard the category.
Now obviously not all religious beliefs fall into this “useless” category, but a surprising number of them do, even ones you might not suspect at first. The easy test is to see if your belief can point to something in the real world that it expects to happen as a result. If it can’t, then you’ve just managed to tie some pretty words together and call it god without actually affecting the world.
If you *can* point to a real-world expectation that comes from your belief, congratulations! Go do science to it.