One of the big problems that Christian apologists have is explaining away the utterly barbaric actions allegedly commanded by God in the Old Testament. Pat Robertson offers his ridiculous rationalization for genocide, arguing that God was showing mercy by ordering the slaughter of untold numbers of people.
Assuming you have a culture that has 1,000 really bad people in it — they’re murderers, they’re thieves, they’re rapists, they’re having incest, you name it they are doing everything horrible — now if they have children, what’s going to happen? Instead of having 1,000, you’ll have 3,000 or 4,000; then — nothing has changed them — then they’ll pass it on to the next generation and the next thing you know you’ve got 10,000 or 20,000 of them and if it keeps on going you’re going to have a million of them. So what’s the most merciful thing for a loving God to do? It’s to take the thousand and get rid of them. And that’s what He did.
“It sounds cruel but in the long run it’s more merciful. Further, He didn’t want his people to be contaminated by those people…. They had sex with animals, they had incest, they did all of these terrible things and they offered their children as sacrifices to their gods, it was horrible what they did.”