"Imagine that (...) I say to you, "I believe in the gerflagenflopple. You cannot prove that the gerflagenflopple does not exist, therefore it exists." You can see that this is ridiculous. Just because I have invented something out of thin air does not mean that its non-existence is suddenly unprovable. There has to be some evidence that the gerflagenflopple exists in order to assert its existence. Since there is not, it is quite easy to say that the gerflagenflopple is imaginary. "- 
Atheists sometimes invent parody religions. Parody religions are fun and parody religions can show up why real religions are wrong.