The atheist doesn’t refuse to believe gods exist anymore than they’d believe the Queen of England doesn’t exist.
It is possible there is a God or gods. It is possible there are none.
There is no evidence for gods. You cannot point to a rock and demonstrate gods. The suggestion that the universe is proof of the gods is just that; a metaphysical suggestion.
There are several arguments for God and ultimately, there isn’t anything in themselves that is compelling. The same is true of arguments against God. All rational arguments are accepted as true because of our dispositions prior to having heard arguments at all.
The question of God is valid because of a question about the world: why anything at all?
Each of us hearing about the gods respond based on the totality of experience, from our impressions about the world.
In this way, we all have beliefs about the gods, or we don’t know what to think about them at all.
To say “I know there are no gods” is entirely a statement of knowledge in the very same way we know “I exist”; for belief and doubt must be justified and “it may be true that x” doesn’t justify either belief or doubt in the case of the gods. It cannot be said, however, “I know there are gods”, counts as knowledge; for an impression there are gods, lacking any demonstrable empirical experience, remains metaphysics. This is aside from knowing the god of which we speak, defined as ineffable. The very thing we assert is unknowable.
Damningly, we can doubt any statement about how reality relates to the gods and vice versa. We take things like psychology, morality, reason and the like as brute facts. And while we may dig beneath these and actually find they are fact, but not brute, what explanation we’ll have unearthed is another fact, and eventually we’ll end with brute facts. None of them being God. It is true there may be a God, or a host of them, but it is no fact and the best we believers can do is explain our impressions of the world and show what matters about them.
That will never be done with words, and Christian apologetics is the most illogical, fruitless activity a believer could indulge. The biggest obstacle certain believers have is in presuming what goes on in the minds of folks who do not think like they do.
The two largest here is that the doubter doesn’t doubt but rejects, and, that the believer has no grounds for belief. One has the impression there are gods. The other does not. Both, if they decide to argue, only do so by asserting, “my impression is true”, which is to say, “my impression is better than yours” no matter how politely the validity of any case is made. It communicates nothing more than this.