If you've watched any number of movies or read any number of books, you're bound to run across this situation. The good guy has a chance to kill the bad guy, thereby saving any number of innocent lives
and millions in property damages and says something to the effect of, "I will not kill this Evil Bad Guy, Slaughterer of Cities and Eater of Babies, because I am not God, and it is not up to me to decide whether this man lives or dies."
That is bullcrap.
So maybe the good guy isn't supposed to shoot Mr. Evil Bad Guy in the brainpan and eliminate the need for seventeen sequels, but the whole "I-am-not-God-I-don't-make-this-choice" is complete horsepucky and an insufficient excuse for not saving all those innocent lives from serving as Mr. Evil Bad Guy's cannon fodder.
We are God every day of our lives. Every day, we choose to not stab those closest to us. We choose to not run over that stupid jaywalking pedestrian who chooses to cross the road directly in front of us. We choose to not walk into our place of school or work and blow up the place. In the last case, it may be due to a lack of access to explosives but the other two situations are easily encounterable. While we may be horrified by the thought of plowing over said stupid pedestrian, it doesn't mean the power over someone's life did not rest in our hands in that moment of time.
We do play God to other people. We just tend to choose that they should live--to play the gods of good. Sure, there are consequences in this society to choosing that they should die, but if we did make said choice, the target of our decision would still be dead, and we would have chosen death for that person.
Psychos and other murderers and abusers are those who choose to play the gods of evil.
But we're all gods. At least, when it comes to life and death and other people.