After reading all the strained logic (on the order of proving that bumblebees can’t fly) used to prove that evolution is impossible, even though we observe it in nature (and therefore Goddidit), it’s a relief to read a fairly straightforward logical argument in the other direction. This one is from Inimicus Dei: “Is the Concept of a Necessary Being Logical?”
…A necessary being, by virtue of it being necessary, must exist in all possible worlds. Because God is a necessary being, he must exist in all possible worlds, and since our world is a possible world, then God must exist in our world…
Ask yourself this: how many possible worlds are there? The answer: there’s an infinite number of them. Indeed, you can posit a world with only one atom, a world with two atoms, one with three atoms, etc. By merely counting atoms, you arrive at an infinite number of worlds. (It is important to note here that by “world” I do not necessarily mean “universe” as in the time-space/matter-energy kind of universe we live in. It could be a non material world or whatever else. The only condition is that the world must obey the laws of logic, thus the term “possible.”)
Now when faced with infinity, one can be certain of one thing: everything – and I do mean everything – will happen at least once. That means that there will be a world with one atom, a world with two atoms… and – tadaaaaaa! – a world with no atoms at all! (You know where I’m going with this, don’t you?)
Similarly, if you have an infinite number of possible worlds, then at least one of them will be without a god! That is required by logic. It follows then that the concept of necessary being is flawed, as it is contradicted by logic. Just as a bachelor cannot be married, a being cannot be necessary.
Therefore, God’s existence has not been demonstrated.