Questioning the Holocaust

In society there's always gotta be some people who stand up for what they believe in. There's always gotta be those people who know the difference between right and wrong. But int he holocaust why didn't these people take a stand? So what if i meant being killed maybe your one action could lead to so many people standing up that your death was worth it! Why didn't any one take a stand take over. why didn't other armies take over? But another question better yet why did Hitler do these things? Like, are you ignorant? Honestly, you have such a good life for yourself you don't have to share it with anyone but you still think that the world is not good enough that you were sent here to make it better? Honestly come on? Don't have so much hope in yourself that you honestly think that you are meant to CHANGE THE WORLD! Get real. But yet again is this how the world is meant to work? But if it is why that way? Why in such a harsh way that so many people innocent lies are destroyed over it? Why?