A common objection to Christianity and God’s existence is “What about the Crusades?!” or some other wrong done in the name of Christ.

That argument fails on many levels.  Feel free to copy and paste these without attribution.

1. You don’t judge an ideology by those who violate its tenets.  Don’t blame Jesus when people do the opposite of what He taught.

2. I make it a habit not to apologize for things that happened 1,000 years ago and that I didn’t do.

3. If there is no God then there is no moral grounding to criticize any of those things.

4. None of those things disprove the central claims of Christianity, such as the physical resurrection of Jesus, his divinity, etc.

More here.