Really, what harm has Christianity caused and scripture caused?

Let's see.... just off the top of my head....
The crusades, the inquisition, the burning of witches, hundreds of religious wars, genocide of various "heathen" peoples, the retardation of scientific progress that could have improved the lives of people, and millions of individual cases of oppression, discrimination, imprisonment and torture.
Did you really need to ask the question? I'm sure you've studied history, and you're not stupid. And while you may disassociate your particular neighborhood church from any such acts, the fact is all of these acts were done using the "scripture" you so revere as inspiration and justification.
Have you ever read your scripture with a critical eye? Your God of the old testament is a straight up sociopath, plain and simple.