I’ve been reading Joshua and was struggling a little with all of the mass killings – the wiping out of whole populations of cities with no mercy. I think such a thing goes right against the grain of the modern-western conscience (how “moral” and self-righteous we can be at times) and it can be a struggle to understand God commanding it.
But I came to see that God was acting no differently than He did at the time of the flood or with what He did to Sodom and Gomorrah. The only difference was in the method of dealing with the evil in the land. In one case He used water, in another He rained down fire; with the evil population of the Promised Land He used an army of men.
In each case He also saved a family: Noah from the flood, Lot from Sodom, and Rahab from Jericho. I wonder how much the latter reflects the state of the people of the Promised Land – that the one most “worthy” to be saved from the destruction of Jericho was a prostitute.