Your heart is in the right place. But your view of history is childlike.

What would you do if a Muslim army came to your town, took your wife and children hostage, abused them, and forced them to convert to Islam? Would you just say, oh, better be nice to my neighbor? That is not a virtue. In fact, it is the abdication of virtue.

This is the reality of why the Christian Crusades happened. They were a response to the Muslim crusades rather than being the initial instigators. Read primary sources.

This book is a good place to start.