A lot of atheists hold that although they don’t have any evidence that God exists, and therefore don’t believe in God, he might exist. It’s just very unlikely.
One of the atheists who hold this position is Matt Dillahunty, who compares the atheist’s position on God’s existence to a trial verdict. In a trial, the defendant is not found to be innocent, they are found “not guilty” – meaning that there wasn’t enough evidence to convict them of a crime. Analogously, according to Dillahunty, the atheist is not finding God innocent of existing, i.e., concluding that God does not exist. Rather, he is finding God “not guilty” of existing, meaning that there isn’t enough evidence to conclude that God exists.
I agree that there isn’t any good evidence for God’s existence, but the conclusion Dillahunty draws is not the correct one.
I like the analogy to a trial, so I’ll stick with that. Before a trial is held, there is a preliminary hearing to determine whether there is enough evidence to warrant even having a trial, which is a lengthy and laborious affair. Similarly, before considering a position, it is necessary to have some evidence indicating that it might be true, and is worth investing one’s limited time and energy in exploring further. Positions that fail this initial inspection are “arbitrary.”
Once we have concluded that a position is arbitrary, there is no need to consider it further. We are not obligated to assign it some “degree of probability,” since it has no relation to our knowledge, and hence there is no basis for such a probability assignment. Nor are we obligated to say that it is “possible” or “might be true.” A claim is possible, epistemically, if there are some facts in its favor, but there are no facts in favor of a claim if it is just an arbitrary assertion.
The correct position for an atheist to hold on God’s existence isn’t “it’s very unlikely, but it might be true,” it is “I have no reason to consider that idea.”