One more heavy question

There are alot of heavy questions out there for believers. By believers I mean those that believe in Jesus; not people that believe in String Theory, or Santa (not that those 2 are at related - though I'm sure Santa uses string in his workshop). Yes that was a joke.

Here's one more big one: how is it okay for a soldier to go to a Afghanistan and kill a member of the Taliban, and it's wrong to bomb an abortion in Topeka or gun down an abortion doctor in his front yard in Denver? Is the cause of the unborn a less worthy cause than anything going on in the middle east? Is it the fact that it's an abortion doctor here in the U.S.? If so, then is it okay to go to Stockholm and take out someone killing babies? Just a question (or 2 or 3) that's been rolling around in my mind for a few years. I'm not a pacifist or anything, I just wonder about these things sometimes.

I promise the next question won't be so heavy! :) Maybe I'll ask about powdered vs. chocolate donuts.