Christians who don't think there religion is harmful?

1347, 15 towns all around Germany round up around 30,000 Jewish people, and burn them alive. They did this because of the bubonic plague, and fear of there supposed God. They did this to appease there God, and to use the Jewish people as a scape goat for everyone's hate. By the end of the century the Jewish community was almost wiped out in Germany, and all they were guilty of was being a different religion. Now I know most of you don't care about that anymore you will probably chalk it up to the dark ages, and fear. But can you say that your religion won't do this again? I mean what if something happens in the future, something so terrible that you only have your God to turn to. And your God wants blood....Will you not fill his unquenchable thirst for sinners blood?Can you say that in these modern times people are less likely to kill people in times of tragedy? Fear can make sane people act on insane thoughts, in times of extreme fear most people will throw reason to the wind. Can you say for an absolute certainty that no Christian will do this? Thanks for your input.