Was the bible a reason or a just an excuse for crusades?
I know this question might sound a little like an attack, but it's not my intent. I might not have the words to perfectly describe this problem in english as it's not my primary language, but I'll try my best. So i was wondering for quite a while about how christians nowadays see the history of crusades and other acts that currently seem kind of like hate crimes. I believe that crusades were political and had little to do with actual religion (much as I believe what ISIS has done recently is a matter of politics more than following the Koran), but at the time of them happening the ones who were popularizing them used the Bible to justify their actions and beliefs. I know that nowadays a vast, vast majority of christians think crusades were wrong. And I know crusades weren't the idea that came straight from the Bible but more a matter of an interpretation that is now considered wrong, which is understandable as heads of the church were only humans, they could've made a mistake. But what matters to me is whether, as I asked in the tile, christianity nowadays sees the Bible as a reason or as an excuse for crusades, inquisition, witch hunting etc. My idea (that might generally be wrong, I've read the bible, but that doesen't make me a theologian) is that the Bible might be interpreted in so many ways and there were so many translations that you could justify any action like the crusades or prove that they were wrong using practically the same verses.
And it's important to me, because if you consider the Bible to be the reason for crusades it means that the Bible, which is the very basis of christianity is encouraging hate crime. While if you assume it was just an excuse, it means the Bible isn't a perfect determinant of moral standards as it can be interpreted in many, often opposing ways.
I asked this question to many christians i know irl, but i guess it's either wrongly formed or simply hard to answer as no one ever gave me any answer. As I mentioned I've read the bible and I actually became an atheist after reading into the Old Testament, I used to be catholic. I don't want to be an antitheist and try to prove christians to be wrong, after all neither can i prove the bible is wrong nor that it is right as faith is a matter of, well... faith, it doesen't require proof. If there was solid proof it would be knowledge, not faith. I hope my question makes sense at least a little and thank you to whoever took their time to go through this semi incoherent babbling and respond to it.