And to the question, the Canaanite genocide, it is one of those cases where something is good just because God says it is good. God can say in one place that Abraham can marry his half sister, and in another place that someone can't marry their half sister.

Christian doctrine is that no one is allowed to punish the sins of the father on the son. So under Biblical law, the Canaanite genocide was sin, as babies were killed. But it was a case of God telling someone to do something He normally forbids people to do.

It is against God's law to strike a man who has done nothing to you, but in this case the Law was trumped by God setting it aside, as by definition something is good simply because God says it's good, not that there is anything inherently good about an action.

So, the answer is that genocide is forbidden in Biblical law. And that's the truth, even though God once commanded genocide.