You don't have to belong to a church or a christian "group" to be a christian. You simply have to believe in Christ, his teachings and that he was the son of GOD, that is what being a Christian is all about. Throughout History all groups of people have used every Religion as a justification of mass murder.
Don't think Christians are any different. The Crusades were "Christian Holy Wars" and they killed Millions all in the name of GOD. Salem Witch trials, the inquisition, and the list goes on and on with Christians at the helm.
However to Conservatives if someone kills a mass number of people they are not a Christian even if they say they are, but if a Muslim kills a mass number of people then ALL Muslims are just as guilty.
Bill did it because he is an idiot who has not taken the time to properly research the story. That being said, if you read Breivik's manifesto, he goes into this whole thing where he says that even European atheists are are Christians, simply because they grew up in a culture dominated by and based on Christian values and principles, etc, etc, etc. So you must be careful of labeling Breivik a Christian, just because that is what he claims he is. His guidelines for what constitutes a Christian, are very different than the majority of people's.
That being said, I am not saying one way or the other, whither he is a Christian or not.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.