God was sitting in heaven one day when a scientist said to Him, "God, we don't need you anymore. Science has finally figured out a way to create life out of nothing - in other words, we can now do what you did in the beginning."
"Oh, is that so? Please explain..." replies God.
"Well," says the scientist, "we can take dirt and form it into the likeness of you and breathe life into it, thus creating man." "Well, that's very interesting... show Me."
So the scientist bends down to the earth and starts to mould the soil into the shape of a man.
"No, no, no..." interrupts God, "You have to use your *own* dirt."