The challenge that I see in this is that categories seem to be so binary in this setup. It is following a logical fallacy that seems to be saying "people have done some terrible things in the name of religion, therefore religion is terrible." By extension, it also seems to be suggesting that beacause someone rejects "religion," (i.e. they are atheist) they are better than those who don't. I've lived long enough to see some pretty incredibly, life-giving people, some who were atheist (or agnostic), and some who followed deeply some faith tradition or other. I have also seen people (and all readers here must have too) who have been pretty horrible, doing horrible things, who have been "religious," but also who have had no particular religious basis for their actions/lives.
I've seen it debated on Reddit (and elsewhere) whether one can be good or ethical or just or moral...etc. if they are atheist (usually discussed as a rejoinder to people coming from a religious perspective, who might claim that it is not possible). Again.... you can find some of the best and worst of humanity motivated by one 'god' or another (defined as "on what do you center your life") Those who "believe in" a god no more have a corner on the market of human goodness (or badness) than those who do not hold such a belief.