Christian philosophers and theologians explain that there are causal links between mass murder and atheism. Atheism, lack belief in God, have the following characteristics that can lend itself to mass murder and can explain why the greatest mass murderers were atheists:

*lack of recognition of an ultimate judge of moral actions and a judge who sets injustice aright in a last judgement, and thus do not recognize the immorality of murder.
*lack of seeing the importance of human beings as images of God and so easily discarding them as merely material things, products of mere chance.
*lack of acknowledging an external standard of moral perfection, thus ending up with self-created standards which can include killing for political survival.
*absence of guidance by divine revelation of the moral law, such as "Thou shalt not kill".
*following an ethic of atheistic evolutionism that is based on the survival and victory of the fittest, which is ultimately a "bloodthirsty ethic", the words of Joseph Ratzinger, that is an ethic that is eager to kill and to maim. This ethic is about conquering others rather than self-conquest.