Wasn't this the plot of a Star Trek TNG episode? I seem to remember something about the Klingons cloning their version of Jesus and then using it as a political pawn, only to have it exposed and rejected as an impostor. Something like that anyway.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'