Why did people become Nazis in World War 2?

They mainly didnt have a choice. They were often threatened into it by other Nazis saying if you dont join up we will kill and beat up you and your family. They were often horifically terrified as of it. But some believed they were doing the right thing and there was no wrong in trying to rid the world of some ' bad sins and people.' Which is quite sad as everyone has some bad sin in them no matter how nice they are its in their past and cant be rewritten.

Hope it helps