The crusades were not inspired by God the Father or Jesus Christ. Satan, as well as God, has a hand in all human hearts. Or would you accept me ascribing the horrors of Stalin to atheism? If someone says "I am a Christian" and then goes on a killing spree, does that mean his actions are consistent with Christ's teachings? Does Stalin saying "I am an atheist" and then murdering tens of millions, make his actions consistent with atheism?
Think about it.