For many centuries, philosophers have debated this question: ‘Does God exist?’ Surprisingly, they have paid rather less attention to this distinct – but also very important – question: ‘Would God's existence be a good thing?’ The latter is an axiological question about the difference in value that God's existence would make (or does make) in the actual world. Perhaps the most natural position to take, whether or not one believes in God, is to hold that it would be a very good thing if such a being were to exist. After all, God is traditionally thought to be perfectly powerful and good, and it might seem obvious that such a being's existence would make things better than they would otherwise be. But this judgment has been contested: some philosophers have held that God's existence would make things worse, and that, on this basis, one can reasonably prefer God's non-existence. We first distinguish a wide array of axiological positions concerning the value of God's existence which might be held by theists, atheists, and agnostics alike. We next construe these positions as comparative judgments about the axiological status of various possible worlds. We then criticize an important recent attempt to show that God's existence would make things worse, in various ways, than they would otherwise be.