Well, there are two kinds of people in the world, my friend. Those who show up and those who get Eastwooded. You get Eastwooded. - William Lane Craig

Hitchens: I've got another question for you, which is this: How many religions in the world do you believe to be false?

What good does it do to pray about anything if the outcome is not affected? I would say when God chooses which world to actualize, he takes into account the prayers that would be offered in that world. We shouldn't think prayer is about changing the mind of God. He's omniscient; he already knows the future, but prayer makes a difference in that it can affect what world God has chosen to create.

There is one important aspect of my answer that I would change, however. I have come to appreciate as a result of a closer reading of the biblical text that God’s command to Israel was not primarily to exterminate the Canaanites but to drive them out of the land. It was the land that was (and remains today!) paramount in the minds of these Ancient Near Eastern peoples. The Canaanite tribal kingdoms which occupied the land were to be destroyed as nation states, not as individuals. The judgment of God upon these tribal groups, which had become so incredibly debauched by that time, is that they were being divested of their land. Canaan was being given over to Israel, whom God had now brought out of Egypt. If the Canaanite tribes, seeing the armies of Israel, had simply chosen to flee, no one would have been killed at all. There was no command to pursue and hunt down the Canaanite peoples.
It is therefore completely misleading to characterize God’s command to Israel as a command to commit genocide. Rather it was first and foremost a command to drive the tribes out of the land and to occupy it. Only those who remained behind were to be utterly exterminated. There may have been no non-combatants killed at all. That makes sense of why there is no record of the killing of women and children, such as I had vividly imagined. Such scenes may have never taken place, since it was the soldiers who remained to fight. It is also why there were plenty of Canaanite people around after the conquest of the land, as the biblical record attests.