Guess what: we don't actually have eternity to play Angry Birds. Right? It's pretty shocking. Luckily, we don't have to think about our mortality too often. Unless a big disaster strikes or someone close to us is sick, we can usually go about our lives without worrying about that kind of big-picture stuff, and it's a good thing, too. (We think.) But the characters in There Is No Dog are obsessed with these questions. Since this is a novel about God it even gets to ask questions like why is mortality a thing in the first place? Isn't a God that would do that cruel? The answer? Yes and no.
In There Is No Dog, life is beautiful because it is brief.
Mortality is a curse. Given the choice, anyone would choose to be immortal rather than mortal.