Do you know about the square root of negative one? It is considered an "imaginary" number, however it allows the mathematics of very real things to work out.
When we say there can be 10 or more dimensions, we are talking about a feature of the math. It is not a place where entities can exist.
Meanwhile, the definition of "God" remains uncertain. If an entity sparked the Big Bang using energy that already existed, but didn't actually create life on Earth (except that starting the universe in a certain way was necessary to allow for life to eventually start naturally), is that enough of a God for you? Such a God would not have to have creating an afterlife as part of his job description. It wouldn't require him to create a good and a bad afterlife and judge who goes there.
Alternatively, the universe might be natural, and some powerful alien eventually evolved, and maybe he is judging us. So, do you want to worship the judge even if he isn't our creator?