Can you please cite your referances or tell us where those stats come from.
I agree that current history has show that war, murder or conflict in the world can be done in the name of any idea or cause not just in the name of a "god" but I think it may be foolish to dismiss the fact that millions have died do to choosing or regecting a religous belief system.
The "Thirty Year War" that occured from 1618 to 1648 had a death toll of somewhere between 6 and 14 million. Most scholars and secular sociologists and historians agree that the primary cause of this war were religious intolerance in the name of "Relegion" I.E. My GOD is the right GOD and only WE know how he should be worshipped and YOU will be destoyed if you do not agree.
The crusades, while not a war so to speak killed over 9 million people in the name of god and religon.
The Israel Palistine conflict has claimed hundreds of thousands.
In addition I think we can also include murderous atrocities in the name of religon such as the witch hunts of Europe and America. Over 2 million men, woman and children were burned to death during this time.
While these few examples do not come close to the 62 Million that were killed in WW2, it does not invalidate the fact that mankind has killed each other off in amazing numbers over whose god is bigger and badder.
Is it your contention that Atheism is an evil belief system because humans were killed under non christian governments? Using that logic, Chistianity is also an evil belief system.