So, I'm playing a Lawful Good Cleric (domains: War and Magic). The other players get upset when I make them let enemies go who beg for their life - I usually give them money also (a few gold). The other thing they think is odd, or wrong, is I will coup de grace an enemy if I have the chance (basically, d&d speak for cuttting off their head while they are knocked down). I say, if the enemy wants to make a new start, and begs for his life, you should let him go. So far, our DM hasn't screwed us with this - they usually will go to the Temple like I tell them, and convert. One guy we met even became a cleric - he's now a CG 2nd level thief/1st level cleric. So I say the Dm is using the idea that Good redeems it's own, which is basically what he said.
But the other players can't understand why I will turn around and Coup De Grace another enemy. I say this is the middle ages, and I'm a cleric of WAR. Your enemies get a chance to repent and convert, or at least surrender, and then they die.