The famous atheist & polemicist Christopher Hitchens has dared a challenge in which he even claimed no one has ever disputed yet. I think his challenge is meant for some of the believers...
The challenge is this:
"If it is to be argued that our morality or ethics can be derived from the supernatural, then NAME me an action -- MORAL action taken by a believer or moral statement uttered by one that could not have been made or uttered by an infidel."
"But If I were to ask you, can you think of a WICKED action that could ONLY have been performed by someone who believe they were on an errand from God, there isn't one of you who would take 10 seconds to give me an example. So what does that tell us? I would say it tells us a lot..."
YouTube - Hitchens Challenge