Halo

So today my brother Ian was recounting at great length the plot of the Halo novel he's reading (yes, they decided computer games weren't enough and wrote books) and since I was racing to finish a mohair scarf (unpleasantness all over me-- wore an apron, which helped) I listened.
Turns out humans in this scenario are called the Reclaimers, the appointed protectors of the technology (handed down to them by the Forerunners) which is able to save the rest of the galaxy from the evil infiltrating of the Flood (a malevolent parasite which zaps the brains of higher life forms so they can live off their life and turn them into fighting machines). Forgive me if you know all this-- it was new to me.
"Wow," I thought, "imagine knowing that you yourself bore such a responsibility just because you were born human! The whole galaxy depends on you living up to your birthright. Imagine how that would make you look at other humans: knowing that you were all in this together, were part of a high-priority project to save the galaxy-- it would revolutionize the way you treated people, even people you didn't know."
I'm sure you won't be surprised by the real-life tie in, but God did have to explain it to me (though it was sort of a flash down-load between stitches):
Halo got it righter than they knew. Humanity is the appointed protector of the world, placed here by the Forerunner Himself to fight evil in every form and to keep other people from being turned into malevolent tools of the universe's greatest Enemy. Every generation has been born to it. It's our birthright. We are each essential pieces in a high-priority project to save the galaxy. Duh.
God's most pointed point, however (between stitches), seemed to be that last bit: how does this fact revolutionize the way I treat people, even people I don't know? If we're all in this together, I don't want to be shooting my own. I don't want to either be or inflict a casualty of/by "friendly fire."
The stakes are too high.