That's not what Islam says. What kind of religion would condone violence?
If you follow that kind of logic, what would you consider the Crusades?
Did you ever read the Islamic books? So go read them before you say something like that.
Where in the Bible do you find the Crusades?! You are mistaken practice and doctrine. Christian practice may be violent, even if its doctrine ain't. Islam however is both, violent in doctrine and practice.
And to the note, many other religions condone and endorse violence. Islam is only the most reckless on doing it.