He then shouted "Allahu Akbar" - which means God is greatest
But the article doesn't make his particular religion clear. So it only makes sense to assume he is most likely in the largest religion that believes in God, which is Christianity, so we know he is a Christian.
And since I have not heard about any Quakers in the news lately doing any kind of axe murdering, I think its safe to assume he is the statistically underreported Quaker, because otherwise we are not spreading the blame for such actions equally on each demographic group, and allowing for the possibility of one demographic having more terrorists than others is racist.
Other things we need to correct is the focusing all the blame of the Holocaust on Nazism. Heck, the vast majority of Nazis did not work at concentration camps at all...
I was thinking he was a fundamentalist Christian - and a Trump supporter as well. Hard to say why he went all the way to Germany for targets.