Dib wasn't religious. A man of science, he denounced the idea of a deity. Chupacabras? Yes. Bigfoot? No doubt about it. Vampires? They're practically accepted as fact. But not God. Not Zeus or Odin or whoever else was seen as a religious icon.
Yet, when the true battle for earth against the Armada came about, he couldn't stop himself from praying to the powers-that-be that earth wouldn't lose.
I don't own IZ. Sorry about the length, I just did this for my resolution.