Please are you really that confused or “only” trying to spread confusion?
Only ignorant can take your point without a second and specific sight!
Tell us if you can what “worst parts” of the Christian Bible can be compared and assimilated to some parts of the Koran!
The definite answer to your rough(and Politically Correct) statement is the comparison of Jesus-Christ’s and Muhamad’s lives and fates! Their first disciples or followers have had also very different fates...
And violence is clearly on the muslim’s side SINCE THE VERY BEGINING.
Last but not least you bring back again the usual Crusades’ stuff without making the begining of a sensible point on that period!
As a straight answer i’d say that Crusades were fully legitimate after the massive attacks by arabo-muslims and afterward by turks against the christian byzantine empire and against “Spain” “France” “Italy”...
But i am wondering if you really believe in your craps and if not what is your goal and agenda
Well, the First Testament is some "worst parts" as compared to the early writings of the Koran, since you ask.
C'mon, the World created in 6 days? A single man and a single woman told not to eat some fruit unless they discover they are naked? Please. And exactly what was "paradise" at that time? Being naked with perfect temperature and no bugs and no wild animals and no bacteria or viruses or volcanoes or earthquakes or floods? Oops, that's right, there was flood over the entire planet in Moses' times. He also came down from the Mountain with Tablets in hand from some burning bush.
Mohammed (Blessing Be Upon Him), from Abraham.