Christian Self Defense?

I'm still hung up on Luke 22:36. Why is the only one that has the stuff about the sword? John, Mark and Matthew don't have it.

I just can't help but wonder if there wasn't just something specific about that exact time that maybe he needed one of his guys to strike w/ a sword in order to heal the servant. You know, maybe for some reason that isn't clear or was omitted from the Gospels because it wasn't something Jesus overtly said, but something he had to do in order to do... something?

It just doesn't seem that Jesus advocates violence even in self-defense. And using that one passage to say we have a duty of self-defense almost seems like the cherry-picking of verses.

I'm not saying that I think we should just let someone wound or kill us. I carry a gun away from work pretty much 24/7. And I know if someone busts into my house, I'm shooting.

This is just really, really bugging me the more I think of it.

I guess I better get finished w/ the New Testament and get on with the Old. Maybe something in there will satisfy me.

Thoughts? Care to instruct me?

EDIT: I guess what I'm feeling is missing is the element of mercy. Wasting the "goblins" (as Kim Du Toit puts it) satisfies the Dirty Harry impulse of justice. I just wonder about the element of mercy that Jesus would most likely want us to display.