1) the crusades, both only left hundreds of thousands, maby even millions, dead just because the two sides were different religons and coldn't get off their high horses and come to an agreemen.
Well, first of all, it was not because of a religious dissagreement. The religion of england at the time was called Christandom (A sect of christianity). And they sent ruthless criminals to take over the city of Jerusalem in exchange for a pardon for their crimes. Sad to say, the criminals went insane and began ruthlessly slaughtering muslims on their way.
That church pretty much was skewed from actual christianity by the king at that time.
2) Joan Tarc (a.k.a. Joan of Arc), one of the greatest French heros, was killed by the English on religious basis.
Joan of Arc, who claimed to be a Christian, claimed that someone (God or otherwize told here to kick the English out of France.) Which goes against the very religion that she believes in which the Bible says: Love your enemies, pray for those who persecute you.
Likewise, she was tried by the corrupt religion of Cristendom in England.
3) Jesus was killed by the Romans because he was against their religion.
First of all, the Romans could care less who Jesus was, it was the Jewish high priests who had a problem with him. Pontious Piolet (The man who had Jesus put to death) said "I find no fault with this man."
The Jews then kept saying Crucify him, and Piolet washed his hands of the matter. "His blood is on your hands" he said to the crowd of jews. "Let his blood rest on us and our children!" they replied.
It was prophesised in the Old Testament (Called the Torah by the Jews) everything that would happen to Jesus including his death.
However, Jesus said, "Father forgive them, for they do not know what they do." even while dying on the cross.
And the plan was that Jesus was meant to die, and he knew he would die on the cross, even when he started his ministry.
4) In the past century, there have been many suicide bombings because of the religion of the offenders
Muslims, who are pretty much the only group that has taken credit for suicide bombings on a regular basis, was created by the man Muhammed for whatever reason, and he added his hate for "Christianity" (Which the kind he reffered to was Cristendom), and the Jews, who claimed to be God's chosen people as said in the old and new testements.
This is why the Muslim religion is the most violent (not the most peacefull) religion known today. The word "Islam" means "Submission" not peace.
5) Hitler used religion (yes, it was a religious belief that Germans with blond hair and blue eyes were supirior) to justify his actions
Hitler was proven to be mentally ill, and the German people were to afraid to challenge his rule.
Well, I g2g, I'll reply to the rest later.