The great flood is a perfect example. Prove to a preponderance of evidence that the entire planet was covered with water and that all of the human beings on this planet are descended from Noah and his family. Provide evidence that in a few centuries, these ark survivors spread to the four corners of the globe, mutated from middle eastern to Asian, caucasian, African, Native American, etc. and in the course of this migration, managed to forget their language, history, and religion. See, if MY deity were to actually flood the entire planet and wipe most of the human race from existence, I would find it pretty diificult to not only forget about him, but to actually make up other deities to take his place.