Yes, but that doesn't mean that God exists mainly in our imaginations as Mogga said.
I have a concept of Donald Trump, but I'm pretty sure that Donald Trump doesn't exist mainly in my imagination.
Heaven is a state of being, not a place.
How do you know that Heaven is only a state of being and not a place? You are implying absolute knowledge of this. Our concept of Heaven is pure imagination, but Heaven could well be a real place.
Our universe is finite and seems to be restricted to 3 spacial dimensions (not sure about dark matter and energy), but space is infinite and could involve higher dimensions. No one knows what exists outside our universe.
