If we do not fight to defend our beliefs, how is our belief going to make a change?
Sure, why not.
Depends which ones but generally so, unless there is good evidence to the contrary.
I would kill and die for them
How else would we make a change?
No. I can't think of a reason that I would need to. Since I cannot be denied my beliefs, I have to assume that you mean fight someone with opposing beliefs. No....I would not, especially since my believe is that I am not permitted.