The crusaders behaved brutally in the name of Christ. The damage from the crusades can still be felt today. The crusaders started with a noble cause, but had terrible behavior. The lesson for us today is that we can damage the reputation of Christ by our behavior even if we have a noble purpose. We need a noble purpose AND noble behavior. The 2nd chapter of 1 Peter has a lot to say about our behavior. Verse 12 says to "Live such good lives among the pagans that, though they accuse you of doing wrong, they may see your good deeds and glorify God on the day he visits us." That's great wisdom for today.
Joke: Why do the people in the Holy Land sleep at night? Because
of the Israelites.
I know, I know, that was a terrible joke.