When it comes to the topic on the Crusades, I believe one of the most valuable things Christians can do is own the history. If Christians deny the atrocities of the Crusades and only focus on the differing theology(ies) the Pope had in calling for men to participate the Crusades, then we are not going to move the conversation forward. Christians should own that part of history and own up the mistakes. The Crusades is a horrific part of the Christian history. Crusaders not only massacred the Jewish people and Muslims, but at one point, Catholic Christians were warring with Orthodox Christians.
If one finds themselves conversing with someone who is Muslim, I think Christians need to be compassionate and even apologetic for this part of Church history. My feeling is if Christians defend the Crusaders it will do more harm than good in the conversation. An apology goes a long way, even if it is for an act committed in the past.
This is what I think but I would love to hear thoughts.