That's malarkey. Those movements were secular religions and personality cults. You neglected to consider the casualties of two world wars and the Civil War, predominantly fought among Christians, and the catastrophic wars in Iraq and Vietnam, initiated by Christians. It's nearly meaningless to refer to "Christians," as you can believe almost anything, from having sex with minor children to handling snakes and speaking gibberish, and claim to be a Christian. It's the world's all-purpose religion, and allows you to do anything. It started among the followers of an other-worldly mage who denounced material wealth, temporal power, the bonds of consanguinity, in order to pursue the kingdom of god. It is now the religion of well-off, family-oriented, politically active nationalists. Magic!