Within the context of 40k, there is little if any good beyond the context of individuals and small acts. The best friend who saved your life multiple times might eat your face tomorrow, hell, you might eat theirs even after all the times you pulled them from the line of fire, and the enemy who merely wants to put a bullet in your head may mean you more mercy and less ill-will than anyone you've ever met.
I thank the writers of 40k for making me feel a little better about reality, now and again, until I get paranoid about their fiction somehow bleeding into it...