Way Up North: Lethal Force: a Christian Response?
I have pointed this out on several occasions, but never with such authority. There is nothing in the Bible, rightly interpreted, which suggests that one may not defend oneself and one's fellows. Indeed, God demands it. Such defense of yourself may even extend to waging war, when required to defend your fellow citizens against an invading enemy.
For a primer on pacifism, see here. If you are looking for a well reasoned and articulated answer to the question "why?", see here.