Many Christians make this odd argument that "deep down inside atheists know that God does exist; they just deny it."
However, it's in fact not completely unreasonable to propose the exact opposite. In other words: "Deep down inside believers know that there is no God. They are just trying really hard to convince themselves that there is."
This might sound like being a smartass, but I'm being serious.
If you think about the arguments that many apologists, creationists and believers present, many of them in fact sound like they are trying very hard to convince themselves that what they believe is actually true. It's like they have this small nagging suspicion buried deep in their subconscious that they are trying to silence and hide, and they are constantly trying to convince themselves that it's not there, or that it's just nothing.
I'm not saying that this is really what's actually physically happening in the synapses and brain cells of believers, but it could just as well be, at least with some of them. I would say it's more plausible than the opposite claim.