Human history says that religion has harmed humanity far more than atheism ever did.
It's not that I'm saying this. Human history says this.
From the dark ages to the WoT. It's always been religion.
Only biased secular/atheistic studies of history say this. This is not a quantifiable fact.
For example, the wars waged by the secular/atheistic nations have been much more brutal and genocidal. Most religions(not talking about "religions" like scientology, but religions with historic mass-following) have laws about war, Muslims have strict conditions of Jihad in which civilians and non-combatants are not to be harmed and aggression(seeking war against peaceful neighbors) is prohibited. Christians had their code of Chivalry.
Wars were fought outside cities to prevent civilian casualties, entire battles were fought with casualties < 100. Only after the rise of secular/atheistic nations were wars waged with such brutality. Cities were carpet-bombed because the logic was "compelling": Massacring civilians was a very effective way of neutralizing the opposition.
These secular minds arose that felt that their intellect was God, they could not see the very narrow perspectives their "intellect" could not see beyond, and they sought to impose their vision on everyone. Visions of a "pure human race" meant that they tried to scientifically eliminate "inferior" human-beings, from the negroes to the jews, to the East Asians that were infected with syphallis and other diseases in bizarre "experiments".
Even now, the western secular elite spreads and diseminates their propaganda with extreme efficiency. They talk about peace, and the value of each human life, while they invade one weak 3rd world country after another, all with made-up reasons that they try to bully everyone into agreeing with. From Korea to Vietnam, Iraq and Afghanistan, they killed millions of civilians in each of these places. They kill men, women, children, the aged without any remorse or human decency. Now, even they themselves admit that the reasons they made up for many of these wars were bogus - various official sources now finally admit that the Gulf of Tonkin incident that the US used as an excuse to invade Vietnam, was staged. Just like Iraq's WMDs were staged. But that doesn't bring back the millions of people that were lost. People like you, average human-beings, lost their parents, some lost their children.
The systematic way these seculars wage wars and efficiently plunder humanity, is unprecidented. And their propaganda machine is so powerful and pervasive, that so many people around the world can't even understand what's happening right in front of them. They can attack your country and demand that the world appreciate all the work they're doing to spread democracy - by indiscriminately killing millions of your fellow human-beings and decimating the country.