God thought it was hilarious when he convinced most of the human race to fight tooth and nail over the driest, bleakest, most uninhabitable region of their home planet. All it took was whispering the same promises and commandments into different ears—he scarcely changed the message, really—to set the whole centuries-long series of bloody religious conflicts into motion.
What disappointed him, however, is that no one but him got the joke. By the time he convinced himself to reveal his messages for the lies they were, the humans had long stopped listening to him.
Finally, he simply shrugged and left for the star Sirius, where a species of much smarter, less gullible creatures lived.