I don't think he was affiliated with a denomination. There is no grand poobah for crazy people who may have been Christians at some point in their lives or at this point no one even knows. The difference between Dear and the shooters in CA is they were affiliated with a mosque.
If he attended the Everlasting Eternal Church of the Living God, they should certainly issue a response like he is our crazy but we don't endorse this. There are too damn many denominations in the US and no central religious figurehead. I will say I never told him to do that.
I forgot to say that the mosque was particularly notorious for being friendly toward jihad. They also went for training in Saudi Arabia. There are no churches that encourage killing people for Jesus that I know of.
I know about Catholicism and the Crusades . Protestants broke away from the Crusader Catholics long ago. If you know of a Christian church that encourages killing Muslims or shooting up abortion clinics , please give us their name so we can shun them and denounce them.
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.