I believe that the best argument is a very famous one proposed some time ago by Bertrand Russell, the teapot argument. If I were to claim that there is a silver teapot which is floating in outer space, somewhere in the asteroid belt, and I have absolutely no evidence that this is the case, no telescope can see it in sufficient detail to identify it as a teapot, nor do I have any explanation of how it got there, but nonetheless I have faith that it is there, would you believe me? And how could you prove I am wrong? Even if you were to travel to the asteroid belt and start to examine all the assorted asteroids and rocks which you can find there, you could still miss a teapot, which is a rather small object that could be anywhere in a very large volume of space, and which from a distance looks like any other object in the asteroid belt. So you could search for this teapot for thousands of years and never find it, yet still not prove that it isn't there. So the question is, why do you have to prove it isn't there? There is nothing plausible about my assertion that there is a teapot in the asteroid belt, and it is perfectly sensible to reject an assertion that is both implausible and without evidence. And that applies to the existence of God as well. We do not have to prove that God does not exist. Nobody has ever given any real evidence (despite lots of obviously fake, concocted evidence) that He does exist, and there is nothing plausible about the assertion that the universe is ruled by some magical being of immense power and unknown origins. It simply makes no sense and never made any sense, and there is no reason to believe it.