Athiest have not killed in the name of athiesm (Some may have, but not enough to make a difference)
Catholics, on the other hand, have killed millions of people in the name of 'god'
Know your history, *ssh*l*e.
Major flaw:
If everything must have had a sufficient prior cause for it to have happened, then God must of been created by something. And that being would have to be caused by something, so on so forth.
