Why do we kill for our ideologies, our beliefs? cant we each believe what we wan

Question:

Why do we kill for our ideologies, our beliefs? cant we each believe what we want without imposing it on.....?

others?
Why do we need these things?
Is it somehow to find stability and security in a world which is dynamic, impermanent, a world where we are unable to find thruth?
We will murder great numbers of people to keep some kind of order in our society, we will kill for our beliefs in god or gods etc.
For what?
Religions or political ideologies, ther all the same.
Do we really need to be so extreme inorder to have order, and where does one draw the line between keeping order and just being a victim fear, insecurites, greed etc.?

sorry english is not my mother tounge.

Best Answer - Chosen by Asker: Some ideologies say that others must believe and accept it as the only one, and that anyone who does not accept it must be killed. Some say that anything that is a threat or opposed to their ideology must be destroyed. Others force acceptance with fear and the threat of death. These are all evidence of an evil will behind them.

( your english is fine)