but didn't christians cause mass amounts of bloodshed during the crusades? (I'm not trying to pick a fight, just merely curious)
The Crusades were justified, up until the Fourth Crusade and the sack of Constantinople. After that even the Pope stopped actively supporting the wars.
It was a response by Europe to aid Byzantium and the Iberian Peninsula against the Moors and the Seljuk Turks in Anatolia. This lead to the Reconquista and the acquisition of the Holy Land, which in itself was not meant to be a permanent state of Kingdoms as the First Crusade was an armed pilgrimage to the Holy Land and the effort to push back the Turks from taking Byzantine cities such as Antioch and Nicaea.
Of course there was bloodshed, and even war crimes. It was medieval warfare, not anything modern wherein we have Rules of Engagement. They had none. Just kill the poor sods until you push them back, if they were injured it was more humane to kill them on the battlefield as a show of respect and honor. Those who use the Crusades as a talking point usually mention the Albigensians, which were condemned by Pope Innocent III because they killed Jews living in Europe, even killing clergy and the bishops who protected Jews in their churches from them.
The Youtube page here is lead by a Historian who works with primary sources in the Middle East and Europe, his specializations are in the Crusades.