Do you believe there is a teapot in orbit around the sun? Most people don’t. But how do they know that?
The answer is that we can’t be sure that there exists no such teapot. Since no one can look everywhere at once, we can never be really sure that such a teapot doesn’t exist.
But it would be really strange if such a teapot existed. On the other hand, it would be quite normal if such a teapot did not exist.
It is the same with gods. We can’t be totally sure that they don’t exist. But if they had existed hey could have zapped a big “WE EXIST” into a mountain side somewhere.
It would be very strange if gods exist. But it would be quite normal if they don’t.