When our thoughts or feelings bristle under God’s Word, He is right and we wrong.
Yeah, I'm sure. Go on then, this should be good.
There are at least two reasons why God did this. The first is evidenced in what came to pass when Israel did not obey God in this command. God wanted the land cleared of all temptations to His people to turn from Him, His worship and His law. The Canaanites were a threat to the purity of God’s people. He had set them apart, consecrated them, adopted them. In giving this order, He was protecting them.
Oh, well isn't that classy. Ethnic cleansing so God's personal cheer squad wouldn't be tainted by new ideas. Presumably, ideas such as not worshipping the cruel and abusive father in the sky. No, I'm sure it's actually a good thing.
Of course one might understand this motive, and still be horrified. These Canaanites were not mere abstractions, but real people. Is it not still rather cruel to kill them all simply for seeking to protect the moral purity of Israel? Perhaps, were that God’s only motive. The second reason God commanded them all to be put to death is because they were all, every man, woman and child of them, sinners. And the wages of sin is death.
Oh, okay. Fair enough. No, really. It's not like he's an all powerful deity who made up these rules in the first place or anything. He had to do it, honest injuns. It's not that he
wanted to commit genocide so that his personal sycophants wouldn't get any ideas about not stroking his ego. He had no choice, his hands were tied, truly.
In short, God did this for the same reason He does all that He does, for the good of His people, and for His own glory.
Gotta validate that massive ego, even if it means genocide. Totally reasonable, I'm sure. I guess it's totally different when Idi Amin does it.